By this logic, 3.5 isn't sufficiently distinct from 3e to deserve calling out, and it really was the book of errata and minor updates it was originally announced as being. Or is it the adjustments to skills that would really be the line, as that's really all that's left (facing and changes to concealment maybe?) that you could otherwise call out.
I think the general premise is that this is more than errata or a new optional book, so it's got to be something, and there's a pretty established language for what that is. I don't think "5e 2024" is easier to say than 5.5, so my money is on the last one sticking.