We enter S4 this month. The fact we still even get some coins for Atlantis could be considered overly generous. We get nothing extra for farming S1 the rest of the time after all.
I get enough Atlantis coins for a couple of pulls and that’s kinda me in there now. S3 will likely go the same way when I finish hard mode off.
In fact I imagine all chest coins will go to S4 now and the same situation will happen in S3…