If it is indeed a cash grab, its a very shortsighted one. You'd probably get more money from retaining new players than from attempting to milk your current playerbase. If I was new to PS2 and found myself constantly being gibbed and one hit killed by shotguns in this era of pump action domination I probably would have zero incentive to stick around and become a paying customer.
You forgot that there's 2 semi-auto shotguns. The accurate quick reload ones, and the extended mag ones. So with the new pump it will be 5 infantry shotguns total, not 4.
They seem about as effective in close quarters combat as the previous set, although the tighter spread will prove more deadly at medium range. My first impression is that the new shotguns are superior to the previous set. It's no secret, well not on PSU at least, that I dislike shotguns in video games with low TTK and a lack of player mobility. I especially dislike ones that are capable of killing players in one shot. As far as PS2 is concerned, the more shotguns they add in the more pointless they make the Jackhammer, which would most probably become too effective when/if they buff it to make it stand out [It should stand out, being a heavy weapon and all]. There's also the concern of the next set of shotguns being superior than the previous set, which seems to have been the case up to this point. Close quarters combat is already dominated by shotguns, I don't see any reason to further oversaturate the gameplay with more. Finally the last thing I want to see is yet another thing that's going to make me go "By Higby's beard! What just hit me?". There are already a lot of OHK weapons in the game. But I guess this is what happens when revenue is on the line i.e. design as many weapon variations as possible for each weapon type as possible.