Edit: For people speculating they will not publish stable release branches or git tags either, TFA does say:
>And to be clear, Linkerd continues to be, and always will be, open source. This change is about the release artifacts, not about code, governance, community, or anything else.
... and all their mentions of "stable releases" can be charitably read to only apply to the binaries provided by them, not the source. But I suppose we'll find out for sure in 90 days.
Edit 2: crb's link is more definitive that the source code will also not be published.