[lmm]

All open source licenses allow the licensee to republish your code - that's part of the definition. It's not going to trigger license fragmentation because any exceptions will make it not open source.

If you want to enforce that other people use different names for their forks, the usual way to do this is with trademarks - this is what e.g. mozilla and redhat do. Npm should respect your trademarks, and if someone else publishes a project under your trademarked name you can make npm take it down... which is exactly what originally happened here.