I am having a hard time buying this excuse. While many towns are indeed growing, it is not like new cities or major highways are sprouting up right and left. I think it would be better to dummy down on some of the "attractions" included in the maps, or decrease region sizes. I know these GPS devices are having a hard time competing with smart phones, but if maps are getting too detailed (and I don't see any other reason for running out of resources), there is seems to me there are better ways better utilize those resources instead of terminating updates completely. For example, do most folks in the UK need all of Western Europe? Do most folks in the US need all of Canada too?
My TomTom came with Australia, New Zealand and South East Asia for some reason. I guess some people would consider that a bonus.