system
Given the following post, respond as if you're commenting on Reddit:
human
Why is it believed black holes preserve mass, charge and angular momentum, but not baryon number, weak isospin and lepton number?
gpt
Basically nobody has a fully quantum mechanically sound theory that relates to black holes,  so people don't know whether they expect these things to be conserved or not. 

I would say these quantities probably are conserved but don't affect the properties of a black hole.  To an outside observer matter never even reaches the singularity of a black hole, or even cross the event horizon if the black hole is not growing. As such there is no time (to an outside observer) for any weird physics to break conservation of these quantities. 
The particles don't actually need to enter the event horizon to contribute to the black holes mass via the holographic principle.