No, not for sure. Since we didn't get a changelog.
Besides a new logo, the faster loading and the live.banks object... I don't think much changed in the Max 8 build we got. Its Max 7 in a new coat.
Even C74 states that the MFL build has a few under-the-hood changes and not much more. The "real" Max 8 is still yet to come in Q2.
The question of what is broken or not will be need to asked again when we get the actual big update.
Not sure why something like the CTRLR app/vst would break stuff, but the errors in the Max window would probably provide a pretty decent clue.
As for scripts, Darren stated he'll do the needed updates when things were finalised. He'll likely confirm this in 3...2...1...
https://cycling74.com/products/new-max-version-8