Can someone explain how exactly does MS acquiring GitHub forces GitLab to move out from Azure? Like is it some kind of fear that Microsoft will meddle with the data or something?
It's simple. Some people don't want their open source projects hosted on a site owned by Microsoft, a company that extremely hostile to Linux and open source for several years was, spreading a lot of misinformation and engaging in many shady actions against it. Now, if you migrate from Github to an Azure-based platform, you are indirectly supporting Microsoft, and some people would prefer to avoid that. I don't think anyone expects MS to meddle with their data in any way.