In the event of an emergency decent, you are talking 8-10K fpm down for any CRJ variant with the actual profile. Automation will auto-recover beyond 10Kfpm in decent, even if you try to manually push more than DOWN 10.0 VS. TCAS or beyond Vmo/Vmm in speed mode. TCAS II sees that in RA/TA mode to the other aircraft, hence the "next generation".
-10KFPM vs -0-... yea... let's see who will change course. 320kts indicated/ 380-480 TAS@ 10-12 degrees down angle (8-10K FPM) vs. straight and level in any other variant.... Let's not get into trig and geometry of that, TCAS II is designed for that already. To make life more "common sense prevails", profiles tend to call for ATC notification.
I can confirm this across multiple 121's and the type training material for a type that can operate at FL510, in this case- automatic/automated decent in the range of 10-15KFPM down to 10K (with respect to terrain) without doing anything but putting the mask on and realizing the problem after the aircraft tells you.
Maybe I am missing something, just going by the bombardier GMM/AMM, plus the FAA approved profile for the CL-65 series. If cabin pressure goes nuts, it's mask and "full down bubble".