I wouldn't call it so much as a cleanse as much as it's yet another attention grab from an industry starving for it. The two things you can always expect out of any superhero comic is promises of a big change, and a return to the status quo not long after. Which is why i always question why anybody would be so upset at any change, cause it sure as shit ain't lasting and you should be used to it by now.
I think it's worth examining reasons why the change might take place and then why it doesn't last. Even if it seems cyclical, it might not be for the same reasons every time.
Like you really think they all sit around in a boardroom and say "ok, we killed off one of our major heroes completely, shocked the world, sold comics, and then undid all that. What should we do next? Identity politics is shocking people now, isn't it? Let's make Iron Man a young black girl to get into the news headlines and change it back once we're bored."
It could just as easily be genuine attempts at innovation and creating lasting change. Change HAS happened. Batman's gone through a bunch of Robins. Even if they're all still on the table depending on what time period or alt universe you want to write for, everyone knows that Jason Todd died. I think most changes are actual attempts at long term modifications to canon. There's just too much at stake at this stage of the game though, too much feedback for it to stick. And some changes do seem to be agenda-driven, rather than "let's tell an interesting story"-driven.
I mean if they make Hulk a gay muslim and plan in advance to revert back to the status quo, they're creating comics disingenuously and in bad faith, right?