I would guess the same. They are very, very popular among the same demographic of rider that regularly upgrades or replaces their horse(s) or their trainer or their gear. The foam panels cannot be as easily restuffed or tweaked to fit a new horse, or even the same horse whose body has filled out. I expect that if you are in the realm of $100,000 horses and $8,000 saddles and $10,000 horse shows, you might continually want to upgrade your saddle(s) seeking that marginal competitive advantage.
There might be a new flavor of French saddle getting popular or they might be getting new CWD, or the trainer might be sponsored by Voltaire.
I don’t think there’s been a sudden turn against them or anything like that. It is possible the leather wears out a bit faster than in the old school British and German saddles.