i expect that VM quit ordering "new " new ones ages ago and are recycling the ones that still ( sort of ) work
if i were asked to recommend a strategy ( fat chance) , I'd say take a year or so to to update & debug the V6 as best you can, than make that the only supported box going forward
much like they are doing with hubs - you want a hub ?, well you can have the hub 3 - in black - or optionally the hub 3 - in white. [ the gamer model hub 3 turbo edition, with the go-faster stripes, has sold out - sorry ]
the hub 1 is almost gone , the 2 and the 2ac will be gone once they can pry the remaining few out of avid gamer's clutches
I think sky have a similar approach - you'd like sky TV : well there's'Sky Q - in medium, or there's Sky Q - in large. - & would you like some sky Q minis with that. all the older stuff is no longer offered.