The stylometry "attack" doesn't get around plausible deniability. For example, for me, two of the top ten related accounts are actually me - but I don't think you could tell which and even if you could be pretty sure I could always say "no" and I think it would leave either you or an observer uncertain. I don't think my employer or future employer would fire me because an account that's kind of similar, lexically, to mine said bad things about the company - or whatever.
If your threat model is people cancelling you for controversial statements - I don't think there's anything to worry about. If your concern is governments or stalkers coming after you - then deleting your account probably won't solve the issue because they'll be able to access archived versions. These actors don't need to "prove" you said something to anyone but themselves. In this case the solution is just not to post anything sensitive regardless of the name you publish under.
If your threat model is people cancelling you for controversial statements - I don't think there's anything to worry about. If your concern is governments or stalkers coming after you - then deleting your account probably won't solve the issue because they'll be able to access archived versions. These actors don't need to "prove" you said something to anyone but themselves. In this case the solution is just not to post anything sensitive regardless of the name you publish under.