Google is like commercial banks, they are not against Bitcoin or cryptocurrencies. They wait for opportunities with more regulations, clearer guides from governments and authorities to step in but don't get big risk for their business.

Similarly audit companies will join cryptocurrency market when chances come and risk becomes smaller for their business.

Google are not fearful of Bitcoin or cryptocurrencies because of scam or fraud as Google accepted many advertisements from bad business. They even are not good with their policies on customer data and more.

Generally traditional businesses are waiting for a right time to join the potential Bitcoin and cryptocurrency market and they want to see a big trigger that seems to be Bitcoin Spot ETF in USA.

Google is a big company, if they continue to persist with the old attitude towards Bitcoin, then in my opinion they are not worthy of being a big company because the progress of the crypto industry will continue to develop.
Not only that, Google's change in attitude towards crypto-related ads subtly shows that the negative fears associated with Bitcoin are not fundamental.

Bitcoin spot ETFs are desired by many large companies such as BlackRock and other large companies because there are benefits behind their application. Google is only now revising its advertising rules and considering a Bitcoin spot ETF.
Bitcoin continues to rise.

Other sources about Google revising advertising rules: bitcoinmagazine

Probably the reason why they're going to do that is because they're planning to get into something big in the cryptocurrency industry so they try and make the sneaky approach by letting the crypto projects get into their advertising and then at the same time make sure and when the time comes, the project that they're in is going to be getting all of the ad space or maybe even the projects that they've invested in will have more ad space than the competition. That's the only thing that I can think of as to why they're gradually going towards this path with the nearing of the approval of the spot ETF.

Just more signs that the ETF approval is coming soon. I mean, if giants like google are starting to taking actions to secure their place in the Bitcoin ETF realm without fear that they might stumble upon regulations and be forced to pay heavy monetary fines for not following them, then that is a clear sign of something about to change. It is always the rich and powerful who get the news first from their other rich and powerful friends.

This will be a welcome development but it needed to be said that google are not afraid of scam related crypto promotions but its acceptability by policy regulated conservatives across decision making Countries but like any product making waves, google have no option than to tilt toward it's breakthrough.

A welcome ideal and many others will follow suit.

While on their ToS, advertising crypto-related products are not allowed on the platform, a lot of content creators in Facebook are actually advertising crypto-related services and products. Those guys have millions of followers and are not being reprimanded or apprehended with what they're doing. Honestly at this point, Facebook should reevaluate their stance with cryptocurrencies as other giants around them have shifted course and has become somewhat tame to it.

I think we’re quickly transitioning from Bitcoin being the Wild West to it being a recognized and legitimate currency.  This no doubt will cause others to follow suit in relaxing some of their policies towards cryptocurrencies as they become legitimate products to be advertised instead of fly by night scams to enrich their founders.

Google's clearly seeing dollar signs in those flashy cryptocurrency coin trusts everyone's yammering about lately.  Makes plenty of sense they've now opened up their big ad network to companies peddling trusts holding the hot digital assets.  After all, hypes simmering at a nice boil these days around cryptocurrency.  And where there's hype, there's eyeballs.  And where companies can grab eyeballs, hey there's profit to be scored for an outfit like Google brokering up those advertisements and 

Id bet Google's bean-counters envision tons of curious folks firing up the search engine to wrap their heads around how trusts built around cryptocurrency work.  More searches means more chances for Google to serve up relevant advertisements and take a slice of the action.  So for them it's a no-brainer move to let cryptocurrency outfits place ads and potentially drive up the company's bottom line.  Whether or not average Joes really understand cryptocurrency coin trusts even after clicking one of those flashy ads, well, Google still makes bank.  So theyre happy to ride this wave and rake in the dough.

This is no surprise to me at all, as the ETF application is getting close to being approved, so we are likely going to see more firms acknowledge and start supporting crypto in their own way; no one will ever want to miss out. ETF getting approved means a lot of great opportunities are going to come up for crypto, and adoption will also increase more than it has ever been.
 
Many people are not accepting any promotion that concerns crypto or don't want to get involved in it as a result of either not understanding it or because they are so afraid of what will come next, but with ETF, there is so much confidence for them, and they can sense some legality now in crypto and will no longer have that fear of doing what the government is against and they might be penalised.

Google is constantly revising, reviewing, adjusting and updating their crypto advertising policy. In 2018,they did it twice.

In all of these the community should be happy because of the positive impact these new guidelines can have on bitcoin mass adoption. First more people would be exposed to it starting with Google searches as there is going to be increased visibility of bitcoin on its platforms. Secondly, scammers would be discouraged too due to strict monitoring on crypto ads.