Nope, that's not what uBlock is saying. YouTube rolls out new adblock detection several times a day. uBlock can't stop it instantly, it takes time for the devs to adjust their code. So for a few hours, YouTube's detection works. If you haven't been caught yet, then it means you've been lucky to get the rollout after uBlock already had a fix. Some of us aren't that lucky. Last week, I got an early rollout several hours before uBlock had a patch. Turned off all my extensions, used default uBlock settings, all their suggestions, had no effect. A few hours later, uBlock had a fix and I didn't see YouTube's block anymore.