We can only assume this was all a negotiation tactic, where they start with an unreasonable position, and force devs to accept an imbalanced (but manageable) fee structure they would have rejected.

I say that, but I also assumed that is what Reddit was doing, but they went full steam towards stupid town, so ymmv.

"were seriously wondering if we can trust unity moving forward"

You can't. If you have to wonder you can't. Unity cooked their goose and showed that they are not your friends and will take every opportunity to fuck you over.

Just your daily reminder that open source alternatives exist, most notably Godot. Free of worries about any fees, let's support and build ourselves a better future.