That could happen at any time that Satoshi or some other early miner with a large stack of dormant coins decides they wants to spend their coins.
And yet, very few have recovered the 50 BTC. Being able to reverse the ECDLP means you'll get all the rest 90-95% that are considered gone for good. This will definitely upset the market. I don't know for how long or how much, but it'll definitely have an impact on your wealth. The fact that they haven't moved since the day they were mined shows that they're excluded from the ones into the actual, realistically assumed circulation.
The “90-95%” is pure speculation.
even sign messages.
For which incident does that go to? The one that says Craig Wright is a liar?