Yes and no. It only really applies to Twitter/X and Twitter clones. You wouldn’t call a Facebook post a tweet, no matter how short, nor would you call a reddit or lemmy post/comment that.
And even then, Mastadon has its own term, toots, and BlueSky calls them skeets.
Until Twitter comes up with a new name in line with their new branding, I think the business should still be referred to as Twitter. But the business should go bankrupt before that happens, hopefully, the lenders need to call in their debts already.