KYC is just going to make them lose players that were playing from a prohibited region.
My friend a PLAT IV user is playing from germany, without a vpn and has had not problems playing on Stake.
Now when he does his KYC, they will notice he is playing from germany, ban his account and he cant play anymore... and well, he will take his action and money elsewhere to play on a sportsbook where he is annonymous as Bitcoin was supposed to be...
I cant blame him and I will probably do the same, take my business elsewhere.
Later, stake
I guess so, I'm sure that there are still many players (even whales) who do not like to submit their personal document.
Of course I also believe that Stake is aware about this possibility so they must be ready to lose some players due to this new rule.
Any decision must have advantages and disadvantages at the same time.
Btw I think some users here have predicted about this mandatory KYC to all users since last year IIRC or since they apply a rule for new registered player to complete at least level 1 verification.