The unlimited private repos for free tier would have happened anyways. You have to remember that this was around the time people were jumping ship from GitHub exactly because they didn't offer private repos for free. It was something many wanted, and they were actively seeking out other places that would give it to them.

I'm not convinced that's the case. GitHub was like that forever, they were well established and the change happened not long after Microsoft bought them. There was no global shift to gitlab instances or Atlassian as far as I am aware.

You can dislike an entity or an action and still acknowledge it also had some positive effects.