Foerest essentially stopped playing after his KoTP AFAIK (which isn't particularly surprising, given his actions during that event).
Sorry I wasn't here when that happened can I get a professional based explanation as to what happened?
Foerest was hating on the random maps that were being advocated so he tried to prove a point that everyone already accepted by choosing random maps every time and continually losing, often not even trying when he could have won if he had. Essentially he embarrassed himself and exodus and that KoTP left a bad taste in everyone's mouths.
Foerest didn't stop playing because of KoTP and whatever may have happened because of it has little bearing. He was still playing afterwards for quite a while in builds which had symmetrical maps up into late november. If i had to guess, he's just busy with RL and lost interest compared to other games like heroes of the storm. Which is a shame somewhat, he was a good player