I allowed Apple to upgrade my macOS from Sonoma 14.2.1 to 14.3 (yea, I know, gluten for punishment) and, good news for you I guess, is that - Yes!  QBDT2019 does in fact open without a hitch.  I still cannot open my own company files at all, so I tested the "sample" company files and was able to open them and poke around a bit without a problem. Even with the "Home" page open, which opens automatically with the sample files.

One extra bit of advice I would like to add is this: I began experiencing MacMail crash frequently immediately after MacOS Sonoma 14.3 installed. You might want to wait until they release 14.3.1 if you use the native mail application and would like to avoid the nuisance crashes.