I don't think Moz made a mistake. Moz is a clever guy. Moz doesn't think he made a mistake. He referred very clearly to the issue in the Q&A with his nephew in July 2021. No sign in that interview that he thinks he 'made a mistake' or 'didn't understand'. Just a sense of resignation and pessimism that nothing has changed in British politics, and that he was attacked because he had 'hit on something':
SAM:
The UK is very inhospitable now, and you were viciously attacked for your political comments two or three years ago. Where do you stand now?
M:
I still haven’t ever voted for a political party in my entire life, and my interest has curdled recently because, well, I was only attacked a couple of years ago because I had actually hit on something. If you talk dribble the press will not print your dribble. They might print a lengthy article on why I should be ignored, but by writing the article in the first place they show their own inability to ignore me! [laughs] Politically, Britain is now a spectacular failure, but I’m perfectly reconciled to the fact that the people will always revomit the same old parties into power. I’m not interested. A harmony of all interests isn’t possible, anyway, not in music or politics or in society. In the first place we always seem to be lumbered with a Prime Minister who, once elected, will not ever represent the wishes of the electorate. There really is nothing to believe in.
Turning The Inside Out. - MESSAGES FROM MORRISSEY - MORRISSEY CENTRAL - Turning The Inside Out.
MESSAGES FROM MORRISSEY on MORRISSEY CENTRALwww.morrisseycentral.com
That "something" isn't the person or the party that he's cut dead.