What you said is true and accounts that have been registered for a long time are still free from KYC, it's just that there have been several emails sent to old users to complete KYC to be able to get more bonuses because some time ago I got the email message.
But KYC is actually not a problem because Stake.com itself can be trusted so there is little possibility of data leakage from users.
Let's hope nothing changes for accounts that have been registered for a long time because most gamblers still maintain the anonymity they want.
May I know what is the contents of that email? because I also made my Stake account a long time ago but didn't receive about increasing KYC for bonuses.
Stake is a big trusted casino here and if it's only to bet a small amount, it's enough to fill in KYC level 1 for a small deposit or withdrawal of a small amount and that's not a problem for me when I want to gamble on a trusted site like Stake.