All the code that has been pushed so far is under MIT and we currently have no enterprise features (/ee folders). The majority of future code will fall into this same bracket.

Some features that are for "enterprise" will be put in /ee folders – ideally we will put all of that in a single /ee folder in the root but we wanted to cover the case where that's non-trivial to implement.

This open core model (that Gitlab use) is popular because it strikes a nice balance between having an open source project (good for everyone) and it puts off bad actors from building a commercial competitor with zero effort.