Testing 6.7.500.0 last week we came across the same issue. It seemed like an easy fix, we had already allowed "All Files" in a configuration profile for our Macs on Mojave, so I made sure the new tcc profile was installing but again we are prompted to manually allow full disk permission.
If it's using "anchor apple generic" that would make sense now. We have testing the install and upgrade on a few machines all with the same result, so it's holding up our move to production upgrades as well.
And I am so in if the splash screen can be made at least scriptable option in the install process.