Union rules require actors to do something to make their name different if someone else is registered with that name. So Michael Keaton would have struggled to get any work at all if he hadn’t gone by a different name.
Not to worry. Based on the OP’s history, the odds of him returning to participate in, or even read, the thread are pretty much indistinguishable from zero.
There is, or at least was, a “SAG thing” about using names, but exceptions have been made for people coming to acting who are already known to the public for the work in other fields. When comedian and future right-wing radio host Dennis Miller did a brief stint in acting, they didn’t want to let him used “Dennis Miller” because of the existence of “Denny Miller”, a big blond actor best known for playing for playing guys with names like “Ox”. Dennis was able to argue that he was already know under that name due to his stand-up work.
A similar thing happened when former Miss America Vanessa Williams went into acting as there already was an actress named Vanessa Williams.
So what? His title was confusing. People see the title, come in to discuss one Steve McQueen, and find out the thread is about another guy altogether. We have nothing in the title that they are talking about someone who is alive.
It’s probably why the thread hasn’t taken off. The people coming in weren’t prepared to talk about the subject he wanted. And they’re frustrated, and his less that congenial posts didn’t help.
He could have just said “Oops. I’ll ask them to put the word ‘director’ to the title.” But, no, he figures out a way to work the word dick in when describing someone.