Good for him to get an offer from a director like Jha but there are so many rumors going on and unless KSG or Prakash Jha confirms it, we shouldn't believe it. Also, regarding his health, just an offer don't prove he is not sick unless we see him shooting right away.
I think what happened with QH is fault of circumstances. KSG might be feeling under weather and he might have decided to get some medical tests done at Delhi to make sure nothing is seriously wrong with his health and at the same time meet parents and get some break to re charge himself. Zee might have not had enough time to shoot KSG scenes in advance and might have asked to delay his tests as QH story is at a high note, which KSG might have not agreed as to not neglect his health and unfortunately things went sour due to lack of proper planning and communication by both parties. I think Indian TV should introduce seasons concept like US to keep story line tight without senseless dragging to clock in episodes and it will also help actors to not lose interest and pursue their other priorities without quitting the show half way through.
Both Zee and KSG should have dealt with it better without throwing mud at each other but hope things work out for better for both the parties.