Those things really needed to face off by Facebook owner since his platform has been abused by so many scammers and it's a damage control for more upcoming scams since if they will not filter those things up for sure there are many scam victims around the world and hopefully there's something regulation comes interms on ICO and IEO so that the scams will be eliminate in the system.

FB didn’t completely ban blockchain/cryptocurrency ads on their platform.
It’s depends on what kind of ads that you are promoting.

More info about this, you can check it here:
https://web.facebook.com/policies/ads/restricted_content/cryptocurrency_products_and_services?_rdc=1&_rdr

If you think your ads that you will publish not against the guidelines, you need to fill this special request form.
https://web.facebook.com/help/contact/532535307141067

About their cryptocurrency product (Libra), I think it’s not against their guidelines.
Why? Because they are not promoting the token sales.

   I think it's just a business, Facebook makes money from adds too! Banning crypto-advertising is their move to stop private marketing
from their users. While I had Facebook and crypto-related friends I think everyone advertised something, to be honest it was massively
used by crypto-related users.
   Probably they will allow crypto-adds in the future, but they will set up rules and probably who wish advertising on Facebook
will need to go directly to them.     
   

The banning of all Crypto currency related advertisements was mostly due to a herd mentality that existed at the time, because when one large social media company does something, the rest will soon follow their example. During that time a lot of ICO scams was doing the rounds and these social media giants received a lot of complaints from people who got scammed.

They took drastic preventative measures to ban all Crypto currency advertisements in an attempt to protect their users. The ICO scene has since collapsed and there are a lot less ICO related scams, doing the rounds.

Since the introduction of Libra, Facebook decided to revisit the "blanket ban" on all Crypto currency related projects, to allow their own token to be advertised on their platform. < Centralized authority can misuse their decision making powers > 

There are some good platforms that reward people for using them, steemit, publishx0, some tries on tron network, but I think we are still waiting for some big blockchain social network. People spend time online and people would like to get paid for their time. We already have nice browsers that pays for using them, just for surfing the internet, browsers that pays you to watch ads, and soon we will have social network in the same manner, when that appears people will forget facebook.

Since people started clamouring about the Facebook ads ban, I have never for once experienced the ban because I still keep seeing several cryptocurrency ads on my timeline from users account to sponsored ads. By the way, I haven't heard any news about the Facebook cryptocurrency (Libra Token) for a while now, have the team stopped development or they're keeping things lowkey for now?

They have not actually stopped developing the libra coin but they are taking some time to update the news about the development. Facebook perhaps might be in that hurry to launch their own coin. They have just mentioned the concept but no legal source is been published for the circulation of libra coin.

Facebook is the most widely used social media platform with a number of users and they might surely find benefits after the launch of libra coin but they would need some strong development behind the screen and this would surely take some time. Facebook allows cryptocurrency ads and even I can see some ads on my timeline. Perhaps they only have uplifted the ban because they themselves are launching a crypto coin which would be a major coins used on their platform globally.

There were numerous project before I remembered that has an advertisement on Facebook that has a millions of active user worldwide, A project holder before would basically thinks that Facebook and other social media sites is the best way to gather potential investors to their project, But Facebook and other social media sites take the change to let themselves not be involved on what kind of project scenario will it turn someday. There's also a chance that Facebook likely eliminates their potential competitors since Facebook is having their own coin. Plus these social media platform is centralized and if they allow some decentralized projects to take their ads services, Their users might realize something about the decentralization and might endanger the centralized social media platforms like Facebook, Instagram and others.

They will accept any ads from thier sites because its all payed even we report something suspicious ads we dont even know if the ads will be remove.

I dont know anything about libra i am more focus in other coins than this one since i dont see any benefit in me having that coins.