thanks for the explanation. I do follow some streamers on YT. doesn't this put the average streamer in a tough spot?

From what I can tell, not really. This is not an extreme movement by any means—it's people saying "I won't buy the game and if you stream it, I won't watch your streams." For some streamers, that might be harmful, especially if you have an extremely left-wing audience or one that is heavily LGBT, but those streamers are probably the ones in on the boycott anyways.

The worst a streamer might have is questions of why they're streaming it. It's unlikely to go beyond that, because no one is mad at the game itself—they're mad at JK Rowling and the boycott is, above all else, a way to make sure their money doesn't end in her pocket.

I've seen a lot of game boycotts—this one is literally as mild as they get. No one is sending death threats to voice actors or really, anything outside the boycott itself.