Mike can say anything like he did not regret about his investment decision in Terra and what he lost with this decision, but only he knew of what is his true feeling about that. Same with lazslo who spent many bitcoins for purchasing pizzas for his daughter years ago. Similarly with other early Bitcoin investors or miners who sold their bitcoins at very cheap prices years ago.

Galaxy will be rememeber by this activity and their name will be in Bitcoin history as well as some Bitcoin history book. They will have a role in Bitcoin history but there will be more institutional investors like Galaxy or bigger than Galaxy in future. Individual or institutional investors are parts of Bitcoin adoption growth and history on its pathway to success.

It is not about legal issues here.

Clean or dirty bitcoins are all can be held for a long time as it's barely that police can catch the hackers if hackers don't use their bitcoins for something that eventually traced by police. So if hackers held bitcoins for years they will not lose their stolen bitcoin through sellings on the market or seizures by police.

With clean bitcoins of Bitcoin miners or investors, they can hold their bitcoins as long as they want with big conditions like: storing their bitcoins in open source and non custodial wallets, and avoid custodial wallets, and last condition of backup and store backup properly.

I strongly doubt that those Bitcoins come from a hack or any other illicit activity. Market sell, or OTC, Galaxy must do a thorough KYC on the party they need the sales for.
If the funds were tagged as a result of a scam, it would be impossible for Galaxy to trade with them.

I doubt Galaxy would buy stolen BTC .

I always heard rumours about big player like Galaxy always try to buy clean BTC like the ones coming out of block rewards to ensure compliance with law and regulation and to spare them of headache.
Before doing this big deal, I'm sure they hired people to give a thorough analysis about where the bitcoin came from. Not to mention there are tools for it.

These big players are no amateurs.

That is most probable, but what if verification is not possible? I doubt they would not finance such a big sell, but my thought of Wall Street is that they look the other way if necessary.

Where's the proof for such hypotheses or speculations besides click-bait articles and some questionable blockchain analytics companies that spit out such "claims"?

I didn't dig deep into this but the linked article basically doesn't provide any meaningful solid evidence, just spreads speculation. Motifs of CryptoQuant, besides shilling their existence, are unclear to me. I didn't bother to look deeper into their X burp as I don't want to use X.

This style of news spreading is troubling to be polite, rather plain annoying to be honest (in my opinion).

I assume too that Galaxy Digital did their due diligence for this transaction. It would be hilarious otherwise.

Galaxy digital didn't revealed identity of the person who sold these 80k bitcoins, so we can't say what are real motives of that person for holding bitcoin for so long. But whatever are the motives, this is a classical example of how beneficial it is to hold bitcoin for 10 or more years. These 80k Bitcoin must be bought under 1$ per bitcoin and see the return after 14 years. Likewise our 100$ today in Bitcoin might have staggering value after 10 or 15 years from today.   

This transaction is pretty significant. As Galaxy Digital helped to sell over 80,000 BTC, which had a worth of about $9 billion, that belonged to an investor from the Satoshi era, and was reportedly a part of estate planning, and this transaction made it one of the largest sell-offs for BTC. Even after such a huge amount of BTC hit the market, the price of BTC went down to only ~$115k and recovered in a short time to ~$117k, which shows how strong the institutional support and absorption capacity behind BTC is. This transaction also shows how the market perceived this sale as a controlled and planned liquidation, not as a panic sale. It was a classic example of diamond-hands strategy and a practical approach to hold the BTC for years and selling it for future life plans and investments.

Sure, investment returns will be lower, but do you really think you can outpace Bitcoin as an investment?
Past yields might be gone, but I am. It's sure that any other asset can give you a 1000% return over 20 years, unless hyperinflation hits, of course.