20ish years ago our dept got the idea that we would issue Benelli M1Super 90's and pull the 870's and make them less lethal guns. They only bought maybe 50-60 M1S90s before scrapping the less lethal idea. They kept the M1S90s in service along with the 870's, as well as a patrol rifle program.
Now within the last few years the range staff has become more progressive, and there's talk of getting rid of all the 870s and replacing them with Beretta 1301 or A300's. If it goes through I imagine they will pull the M1S90s as well, Id imagine there are probably only 30 ish out on the street still. They haven't ran a benelli class in over a decade, if someone with on retires/turns it in they don't get issued out again.
I think itd be a good move, the 870 I was issued at first was from 1978. Had to turn it in when i got a rifle, but if i could carry both I would.