you could read this as them trying to pressure PA and the arab compradors to go with russia’s plan.

I have no trouble seeing it this way.

or you could read it as them calling for a veto of the american plan if it came down to that.

This I’m more skeptical of. Like I said, this would amount to openly splitting the Palestinian state, which is something AFAIK Hamas has always put extreme effort into avoiding doing. On top of that, it’s (IMO) nearly certain that a veto would not have prevented this from going forwards. It has the support of the Americans, all the Arab countries, and the PLO. It’s going to happen. Even if it didn’t, the only real important factor there related to the UN vote is the support of the Americans. AFAIK, the UN has never really stopped them from doing anything before. It wasn’t going to start now.