It explains that in the link they posted... So GitHub is essentially outside the scope of the trademark policy, due to the history. We also decided to explicit

It explains that in the link they posted... So GitHub is essentially outside the scope of the trademark policy, due to the history. We also decided to explicitly grandfather some major projects that were using similar portmanteaus, but which had generally been good citizens of the Git ecosystem (building on Git in a useful way, not breaking compatibility). Those include GitLab, JGit, libgit2, and some others. The reasoning was generally that it would be a big pain for those projects, which have established their own brands, to have to switch names. It's hard to hold them responsible for picking a name that violated a policy that didn't yet exist.