See biggest thing about Diwali is lesser days of business opportunities then Eid & Christmas, see in christmas and eid you can release movie few days before the festivals if festivals are on mid weekdays, but in fiwali you cannot release in pre diwali phase without business being affected severely
And while christmas is best for long legs of a movie, Eid & Diwali are quite close but eid has benefit of able to release few days before, but unless diwali is on monday, saturday or sunday, it's foolish to release it pre diwali
And another factor is that Diwali has seen not so good movies too compared to eid and christmas
So content regardless, maximum limit of business can be achieved at christman followed by eid and closely followed by diwali, and also after that Content and WOM comes into play..!!
So basically no matter what TOH does or what happened this year, Christmas >> Eid >> Diwali as far as business is considered, rest is content and WOM..!!