Following the announcement that Microsoft has acquired GitHub for $7.5 billion, I've just migrated all my repositories and website to GitLab. It's sad, but I will not support monopolistic companies in their endeavours to dominate. By all accounts, it's a good move for Microsoft as it is likely to bolster their image amongst young developers and encourage support and use of their proprietary services.
However, this is bad news for open source and free software. Reliance upon any single company is always going to be bad news: they get to dictate what you can do and how you can do it. Free software is not about having something for nothing, but the freedom to make your own choices and from a transparent and open set of options.
GitLab, aren't perfect - they aren't an entirely open source company, and recently moved hosting from Microsoft Azure servers to Google Cloud - however, they do offer some actual benefits over GitHub, like improved CI and private repositories included in their free options (similar to BitBucket).