Which Gitlab? The software is less important than the ecosystem. Git is the major component, but Github/Gitlab are about usefully centralizing it. Gitlab is still a centralized service, even if there are N instances of centralization.

In other words, I don't know how much use it is to fork Gitlab if the community around it is dispersed. Git is already based around decentralization, and I don't see how running my own instance of Gitlab makes it any less disruptive when the most popular instance of Gitlab is disbanded.