It is a custodial platform, so they control they keys and they'll definitely disagree with you on this. I don't use Kraken and i sure don't know anything about KINT token, but i am pretty sure it is a shit token, so i am surprised you spent €5k on that.
That said, if you are sure you didn't receive an email that they were going to delist this token, then that's wrong on their part, because they have to notify their customers about this. Or maybe you missed it, or you just bought the token and forgot about it on the exchange, i reckon it is the latter.
Any coin listed on a CEX platform is not a strong indicator that it will remain listed. Any coin that violates the listing criteria over time may delisted. This is because the coin may be highly volatile or could have been manipulated by its team or similar parties, and such measures are taken by the platform to protect other investors.
In any case, if you do not receive an email notification, they can check the platform’s updates or app notifications to see what actions will be taken regarding the coin. If the user does not notice, the coin may be delisted, though they might still be able to withdraw it in time before withdrawals are stopped
However, it is everyone's responsibility to conduct their own research before investing in a coin.