They do come back more often than not, I agree with you. I've had multiple exes that came back. They come back when you absolutely dont give a single fuck about them. Its like the universe sends them a sign that you are over them for the most part and then they fucking try to creep back in. I had a gf that I was sooooooo needy towards because thats the game she played and never wanted to give something in return and I was a dumb little boy that chose to pursue her more instead of shutting the door for her. Eventually she got sick of it, as expected, and dumped me. I was fuuuuucking devastated for months I think even a year because I was depersonalized and anxious after that rejection. Thought that I would never get her back and that I would always want her. Well I stopped caring and there she was 2 years after writing me long ass messages that I didnt even read I just deleted them. Didnt give a fuck.

So it is very likely that they will return but i think most of them will just come to see if they made the right choice and did you change so the vital part of those stupid bullshit "getting ex back guides" is only that one must as quickly as possible (which doesnt mean one has to force himself because that will also be harmful) move on with his life and accept the outcome.