None of us are lawyers, so we can't say for sure. However, Wolverness sent a tweet about Pore being illegal and somehow deserving of a DMCA. We disagreed and couldn't find a way how that was true.
Pore has no direct reference to unfree software, the only way it can run on proprietary software is though a Sponge implementation, which Pore has no direct dependency on.
So far no one except Wolfe has questioned Pore's legality, so I don't know what you mean by rumors. We have not gotten anything close to a DMCA, so for now the project is essentially sound.