It’s’ really not a canonical legal question, it’s a practical question.
The FSSP and all other traditional priestly organization exist because the pope allows them to exist. He could end them with the stoke of a pen.
He can also remove any bishop from his diocese (Strickland) that permit the TLM.The only traditional priestly organization left standing would be the SSPX.
That would be a mistake on his part for many reasons, so I don’t believe he’d do that. I’m quite certain he’s approach it differently.
But could he abrogate the TLM illegally just as did Pope Paul VI? I don’t there’s any question that he could.
He could try, but I doubt he'd succeed.
Catholics have wised up since the reign of terror of Montini/Bugnini.
Fool them once, shame on them. Fool them twice, never again.