Marriott does not require hotels to offer upgraded award rooms. I tend to see them more at hotels that actually have a larger selection of upgrades (i.e. resorts, etc.). Now whether the upgrade is cash on top of the base award or extra points it seems to be all over the map. I sometimes see cash only options, but I've also seen points only options and both options (which I think I see the most often.)

I do wonder though if hotels, when they do offer upgrades, offer a set number of both points and cash options. I just completed a stay at the JW Cancun and when I first made my reservations, I saw upgrades for both extra points or cash. But after a bit of time had passed, the points option disappeared leaving only the cash upgrade option. So I wonder if all the "points" upgrades were taken leaving only the cash upgrades available?