Any idea whether they'll eventually chip away at public-visibility open source projects?
"We're not Microsoft" might be GitLab's biggest remaining selling point. And the more savvy open source developers might care disproportionately about that. I'd think GitLab might be trying to lure open source, now that GitHub isn't the warm-fuzzy company that originally landed a lot of it, yet GitHub continues to be the de facto official provider for most major open source projects and ecosystems. Plus that has network effects for landing paying customers. Has GitLab given up on that?
BTW, I'm fine with GitLab charging for non-open-source commercial projects. If your startup has more than 5 users, you probably already have salaries in your burn rate, and GitLab is a relatively small cost, for a critical service. (See: TLC's "No Scrubs".) I've happily paid for GitLab in earlier-stage startups.