Is there a link that explains when and who will rotate in and out of 4* availability on token pulls?
I’m sure its right in front of me but am unable to find it.
Thanx
Dudemon
At the moment, the oldest rotates out to be replaced by the newest. So in like ten days or so, Peggy gets replaced by Danny.
At which point, placement, progressions, and bonus pulls will be the only way to get her.
https://forums.505go.com/discussion/62286 has a list
Don’t forget you can also entirely hault your progress on 5’s and new 4’s and save up 6 pulls worth for 1 cover. 
Which is sadly the only consistent one there besides the progression that will happen, hmm nearly once a year in a few 4 star releases. 
Tell me about it. Between the week-long Hulk event and the impending end of season, that’s looking like the only way my Peggy is getting covered.
Don’t exaggerate. Once or twice a year there will be an event where they will award 1 Peggy cover! LOL
Well, I mean, she’ll get covered in just 60 more Captain Marvel 3* covers, assuming no further rework of 3->4* champion rewards.
So I guess there’s that.
Well since there is a captain marvel 4 star, do expect her to change just as you hit 59.