Not in law enforcement, I do have family that is or was, so I hear/heard things. My memory of all the publicly known stuff, news reports, things officers talked about etc.... YES just like you say, it was absolutely a driving factor in CA.
As for LAPD, my memory is their first batch of rifles came from the DOD, m16a1s, of which most had the full auto fire controls removed. These as I remember arrived fairly soon after too.
101 California shooting drove the adoption of semi auto handguns to a large degree in CA, and NHW/BofA drove the adoption of rifles...again at least in CA. I absolutely remember this being the case.
I seriously question a pistol caliber "rifle" would have made much difference if any. These guys were pretty armored. At best they might have made taking shots at their feet or other weak points easier at distance, at worst just slinging more useless lead down range. As others said this was in the days before red dots and LPVOs as we know them for the last 20 or so years so that kind of shot would have taken more skill than the average officer has for most of the incident with a pistol or pistol caliber "rifle".