Yes that was official Sony stance. But question is how many titles would break, 10, 100, all? Sony should devote some resources to test each game and enable/disable Pro mode per title basis, instead of disabling in all ~700 games because a few very specific poorly coded games might break.
There are a lot of people who are in agreement that the way non patched games are handled on Pro is probably its biggest pitfall.
Bringing up MS again, not only many games get performance benefits on Xbox S already, but this trend will continue with Scorpio, if recent interviews and various articles are of any indication. Also we can look at the way MS handles backwards compatibility. BC games not only receive performance benefits, but also improved vsync.
MS can do all that but Sony can't even make original PS4 titles runs smoother on the Pro without everything breaking apart.