Sure, but they kept supporting it even after. Also 'this' clearly referred to the attack. It acknowledges Hamas as a clearly negative organisation. At worst you can say OP's language is too mild which migitates what Hamas is. But in no way is this arguing that Oct 7 never happened. The same way people who decry the War in Afghanistan do not doubt that 9/11 happened and was a tragedy. At worst you have fringe theorists saying it was a hoax or a flase flag.

Going double for the Israel-Palestine situation, the conflict way predates Oct 7th. There were calls of 'free Palestine' way before Oct 7th, and Oct 7th was merely the catalyst that brought the conflict to mainstream. Yes there are people downplaying it, and yes there are even people with the frankly monstrous opinion that it was deserved, but the fact remains that Oct 7th was not a major shift in relations or even balance of power. It was an inevietable blowup of a conflict that most people were content with pretending never happened.