Yes I agree with this, and I agree it’s overreach. I would much rather the union went back to fighting for its members’ interests instead of posturing on fashionable issues that have only very tangential connections to their membership. Palestine is one of these - I don’t see how, in making this such a key UCU issue, they can avoid alienating and upsetting some of their members (and potentially creating conflicts with protected characteristics). I guess gender identity is another such issue.
I would be very interested to know if there are any actual regulations around what unions can and can’t do on these sorts of things.