This news isn't surprising at all. Bill Belichick put his hands on an official, that's against the rules, so the NFL has to punish him. Considering the lack of maliciousness with the contact, a suspension would have been too much.
Las Vegas even set an over/under on the fine, at $50,000.
It makes sense. Kyle Shanahan got fined $25k for pursuing then berating officials after a game. This was one step worse than that as Belichick actually made physical contact.
I don't think there will be many more incidents like this one, especially from Belichick. He crossed a line, the NFL has penalized him, and he won't cross it again.