Yes, he's sede. But still wrong about this. R&R can be schismatic, but to say confessions are invalid due to this is unfounded. He has yet to defend it with a proper citation to a Church authority.
He's got nothing. If he asked Bergoglio, Jorge would say the confessions are valid, due to his great mercifulness and humility, and it's the intention of the "Pope" that determines jurisdiction and nothing else.
But how about the gall of catholic.com in asserting that Orthodox confessions are perfectly valid, while SSPX ones were not (until Jorge said they were) ... because the Orthodox are a Church unto themselves. That's shameless heresy.
So the solution is that the SSPX should start their own "Church" and reject the Primacy of Peter and a couple other dogmas, like infallibility, and then catholic.com would say they had valid confessions by their criteria. Ridiculous.