Regarding the broadcast: I do think something that galvanizes the galaxy so that they’re more inclined to join the resistance would be helpful. The broadcast is probably as good as anything in that regard, given what’s available to work with. But the content of the message itself is so meaningless and vague that it doesn’t necessarily accomplish anything. There’s no reason any of the younger rebels would recognize his voice, and he doesn’t identify himself. But something more than Poe’s awkward “somehow Palpatine has returned” would intensify that scene at the base immeasurably. Is there any Palp dialogue that’s on the cutting room floor from editing other scenes in the film which could be used to either extend the message or replace its content?
While personally I don’t want his broadcast in the movie, I can see that there’s a point where it could possibly somehow be placed in the movie itself: when the resistance is at the base after Leias death, and rose and poe and the resistance find out about the stupid death Star destroyers, you could put Palpatine’s announcement over in that part of the movie, and cut to the galaxys reaction maybe, and then it could flow into the scene where they all head out to exegol and chewie and lando set out to find people. I don’t know how someone would do that with footage but that’s where it could be placed if someone wanted to for their version of the movie