I wouldn't purport to be any kind of categorical authority on the matter. It's just an impression, entirely my own and not based in any particular documentation (as such, I'm aware that it could be inaccurate). Rather, I suppose, it's the lack of documentation that has left me to wonder that his attitude might've softened to some degree—i.e., if Trump's presidency were a particularly enduring sore point, one might expect him to have had more to say about it in some form or other.
If he had adjusted his position on 45 at some point during the feeding frenzy of the past four years (and having himself been subjected to a protracted cancellation attempt during the same period, involving many of the moral crusaders found among the anti-Trump mobs), he wouldn't be the first to have done so. I've noticed it within my own family (specifically, the section of it that resides in the state of Pennsylvania). Given his previously expressed hostility toward Trump, he may feel it inappropriate to suggest that anyone else within his circle reign in their invective toward the dread orange fellow.
This is, of course, all speculation.
If Morrissey's feelings about 45 are as strongly averse as they ever were, it doesn't ultimately bear upon my view of the man. I need not agree with or rationalize his every opinion in order to continue to admire him (which I do). All I ask of him is that he continues to have a mind of his own—and there's more than enough evidence of that being the case, whether his views on Trump happen to align with pop culture consensus or not.