If that were to happen, because *-h is the original ending of locative plural case it should replace *-ma only there.
So, instead of "voziti po pravilima" we would get "voziti po pravilih", the way it should be =)

The *ma ending would definitely stay in instrumental, because it is the ending of that case.

Dative plural would be a tough one to solve…

Aha i see. Thx. :D I do wonder however how would common people react if this was implimented. Overall i see there is a trend in all countries for bastardisation of language in media. Usually wierd mutated speech from the captial is used there + lots of usage for fancy ass words from latin & english just to sound smartass. I damn hate it.