No, they say open source needs to evolve, the implication this is an evolution (not devolution) of open source.
Their announcement talks about how they spoke to OSS experts. That's not relevant: the experts would simply have said: that's not open source.
Hashicorp several times say the BSL is permissive. Permissive is a well established term in software licensing. No, the BSL is not. The BSD and MIT and Apache licenses are permissive.
Finally there is this claptrap from their FAQ:
> 17. Does HashiCorp still believe in open source? > > Yes. [...]