Isn't there already something of a schism with the whole Vatican 2 developments from decades past and how some groups of Catholics practice different masses (among other things)? This sounds like more fuel for the (impending) fire.
@Marshal Mannerheim may have better input on this.
Yes, and I love how I've become the guy on KF you tag when you want to know something about Catholicism.
Before Vatican II the Catholic Church officially taught that Jews were not the chosen people of God, that only Catholics could be saved, and that there was no such thing as a natural right to religious freedom. Vatican II changed that and "reformed" a lot of teaching. Many traditionalists said that this was wrong and spoke up against it. These protests got more vocal when the Novus Ordo (a new rite of Mass that's far closer to Protestant worship than the traditional Mass) got brought in, and one of their leaders was an archbishop called Marcel Lefebvre. Lefebvre was
not happy with the new Mass, and formed his own group of priests, called the Society of St Pius X, that would carry on offering the old Mass. Rome wasn't happy with this and eventually excommunicated him - although they never said the SSPX was schismatic, and have always said they have valid sacraments.
Not all Catholics who use the old rite are SSPX, and lots of them (like the FSSP) are part of the Catholic Church in the same way the church in your neighbourhood is. Some traditionalists (called sedevacantists)
are in schism, and think that every pope for the last 60 or so years hasn't really been the Pope.
The way the Catholic hierarchy has acted, especially during the pandemic, has meant that a lot of Catholics became trads because we were the only ones who kept our churches open, and bad bishops like Cupich only fuel that. There will probably be an actual schism in the future between the Catholics and the people who want "communism with hymns". I don't know what will cause it, but I'd guess that the German bishops pushing for gay "marriage" and priestesses will probably be the spark that lights the fire.