I think Microsoft servers include GitHub? If so, that'd have a huge negative impact on research and academia in EU, as well as software development (even some web pages using JSresources from GitHub pages directly).
ECMWF is on GitHub, and I think they mirror some work in their BitBucket.
Research in Spain has both GitLab and GitHub from what I could see (my company has 2 internal GitLab, a few orgs on GitHub).
Many projects from EOSC or used in EOSC ptojects and deliverables have GitHub repos.
Many projects I use from a Manchester Uni team from ontologies and metadata and provenance are hosted on GitHub.
CERN, Max Planck, INRIA use GitHub, although not sure if exclusively or if they mirror. But I know some of their international collaboration happens there.
So GitLab is definitely used in Eu institutions. Maybe all. But that does not mean GitHub is not also used primarily or as alternative or mirror by these same institutions.
