Many people mention Microsoft's past history as reasons for worrying about this. However, I disagree. I don't think this would be bad because it's Microsoft. I think it would be bad because GitHub wouldn't be a generally independent entity, with no business interests besides making a product good enough that people will pay for it anymore. Currently, GitHub doesn't really have any incentive to care what tools and pla…
A large company doesn't make an acquisition like this without a business incentive. For them, it's driving people to their products. Maybe making the tooling in github for interacting with microsoft-y products a little bit better. Maybe adding whatever licenses microsoft likes to the front of the default licenses you can pick from when you create a new repo. Things generated by their editors going into your .gitignore by default.
I don't see any reason they'd acquire github and then entirely leave it alone.