Gecko was, afaik, the last major browser engine that supported <blink>. Chrome and IE don't, at least. Opera won't, after switching to, ironically enough, the engine called Blink.
So it's not exactly the same as removing <center>: Other browsers already didn't support it.
Oddly enough Chrome/Blink still has the String.prototype.blink method to create a blink tag from a string. If I recall correctly it's actually part of an ES (not DOM) standard.
Wow. Because this surprised me so much, I just found out that if you open up a node REPL and type 'hello'.blink() you get '<blink>Hello</blink>' returned. So I guess it's an ES thing and it boggles my mind.
I was trying to find the ES standard where it's specified but I'll settle for this[1] instead. Interestingly enough you have quite a few HTML wrapping functions as part of the spec.
So it's not exactly the same as removing <center>: Other browsers already didn't support it.