I'm guessing there's no urgency to run out and change the modules unless (a) there is software that really needs it or (b) their techs are not busy (or happen to be there doing other work on the vehicle anyway). The other impetus would be (c) let's not have this huge liability hanging over our corporate head.
(Only issue with the module I've heard is that to render - as opposed to detect - traffic cones, you need the HW3 module)
This also relates to accounting rules. I saw an article suggesting there was a half-billion dollars of unrecognized revenue, which according to the GAAP can only be accepted as revenue when FSD is substantially delivered. If Elon can declare "here's your FSD, it works 90% of the time if the weather isn't terrible, we'll keep improving it but it's pretty much delivered" then he can take that revenue. But offsetting that is the liability that tens of thousands of vehicles need a hardware upgrade. But, the longer he puts it off, the more refined the quality of the modules get. (Every circuit board goes through design revisions and firmware upgrades)