The whole lengthy story of what was going on for years in the TAC, which was an umbrella organization of Continuing Anglicans (some of them) mainly getting its steam from an American Continuing Anglican Church (at the last, the Anglican Church in America) was murky even to other Continuing Anglicans. In the end, the idea of some sort of painless blend of the TAC and the RCC never happened, of course (as most Continuing Anglicans predicted). In the end, a few parishes of the ACA, at least, came in, after Anglicanorum coetibus. The major drive for the move had always been top-downward, and the laity didn’t like what was finally offered.
The final impetus for Anglicanorum coetibus, ironically, wasn’t the TAC manuvering. It was contact between orthodox Church of England Bishops, in late 2008-2009, who sought out Rome for a method to escape the inevitable attempt by the CoE to consecrate females as Bishops. Which opened a door that some TACs also used to enter.
I was posting steadily, back in the day, trying to explain what I thought was happening. And what might happen next. I feared that would be what you suggest in your final para. But I don’t see any figures that might lend light on the subject, currently.