That's not the sequence of events.
1. No later than the early 2000s, senior church leaders became aware of what many American leaders already knew via rumors, that McCarrick was molesting adult seminarians.
2. This finally gets communicated to Pope Benedict around 2009, at which point McCarrick is kicked out of the seminary where he was living and forbidden from lecturing, traveling, and publicly celebrating mass. Except for having to find a new place to live and not celebrating mass in public, McCarrick ignores most of this.
3. After Bergolio is elected Pope Francis, his ally McCarrick ignores any and all restrictions. At this point, it is not clear if Pope Francis lifted the restrictions or they just ignored them. Given the Pope's documented autocratic ruling style, it is likely nothing was formally rescinded.
4. In 2018, there is a credible allegation that McCarrick molested a minor decades ago. Pope Francis publicly re-imposes Benedict's punishments and then strips McCarrick of his red hat, (he's no longer a cardinal).
5. Immediately after McCarrick's punishment, priests, former seminarians, and others launched a Catholic #MeToo movement aimed at the bishops and others in power who permitted the molestation of seminarians.
6. Then the Pennsylvania grand jury report came out. Some of Pope Francis' closest allies, like Cardinal Donald Wuerl of D.C. were implicated in the cover-up to an extent previously unknown.
7. Vigano's letter, while definitely representing traditionalists, probably was encouraged by a number of progressive prelates, like Cardinal Dolan of NYC, who have buyer's remorse with Pope Francis and fear the loss of power an actual schism would bring. And there is a de facto schism that has nothing to do with the abuse scandals.