What would you do if Pope Francis prohibited the traditional Latin Mass and removed Summorum Pontificum?I don't think he will because he doesn't care about liturgy. He's probably clever: giving confession faculties to the SSPX, for example, to throw traditionalists off guard. But given his hostility to trads ("rigid," "Pelagian," etc.), he might. If the TLM were taken away I'd be hurt and disappointed, and wouldn't make any extra financial effort for the institutional church as a result, but I wouldn't leave the church again. If I have Pope Benedict XVI's English Novus Ordo I'm fine, plus, as in the dark days of Paul VI and John Paul II, depending on where you are, there are the Eastern rites.
Nobody before Vatican II imagined the ordinary practice of Western Catholicism would just stop. The Pope has the authority to suppress the TLM and write a new service but like what provoked the Chornock schism in 1930s America, it would be stupid of him.
Writing new services isn't something we historically do. This may be a fairy tale from the liturgical-renewal folks but the story goes that churchmen didn't study the liturgy as history until at least the 1800s, so they were cautious about changing it, lest they cut out something essential. Just pass it along and learn the rubrics. It did change but very slowly because of this.
The SSPX means well but is wrong. Liking the old Mass better as I do isn't enough of a reason to separate from the official church. It was arguably different before Benedict's English Novus because the translation then was so bad. But arguably not, because, bad or stupid Popes notwithstanding, our teachings don't change.