More discussion here:

https://news.ycombinator.com/item?id=36523878

https://news.ycombinator.com/item?id=36523843

How frequent were these incidents before the Microsoft acquisition, compared to now?

I don't have any hard data, but it feels more frequent just within the last year, not necessarily shortly after acquisition date (although yes, changes take time to propagate).

That won't tell you much without also accounting for how much growth the platform has also had.