Because I thought it trivial. What you are mainly asking about re violations is a quite deep area of SM and beyond SM particle physics - mixed in with extreme gravitation.
Merger of 2 NS's is assumed to always end with gravitational collapse into a notional BH. So you're no better off using that example than just a notional BH-BH merger scenario. Except perhaps that in NS-NS case we need not speculate on the 'initial' state (can of worms!) of any infalling matter contained within merging BH's.
Look, I'll just put the current GR community picture and let you think on it. Initially we had normal stars with lots and lots of baryons within. Huge net baryon number. Next, there is collapse to either NS or BH state. Followed by inspiral and merger of such a pair. Followed by, it's theorized, eventual Hawking evaporation.
The last two processes are for sure baryon number violating. Especially the last - since the vast majority of radiated energy would be in the form of long wavelength photons, which of course have zero baryon number. The mass-energy given off in merger event GW's is also clearly non-baryonic.
Whata whata? Say that again - clearly.
Goes back to my initial comment here. You cannot mix and match like that. Disparate conservation laws are just that - disparate. Prevailing GR lore has it that net charge, sans any netralizing from exterior inflows, is strictly conserved during gravitational collapse or merger. I think that charge invariance (not conservation of charge which is a different animal) is very suspect as easily demonstrated with a simple thought experiment - but I don't with to go there this thread.
