The system is fighting it, really. Maybe it's crazy, but, for instance, the 222s simply aren't there for upgrades any more, it is forcing a pair of 211s. For some customers in that situation (many? all?), it is giving a $7 credit for a period of time to offset the extra cost of using a pair of 211s instead of a 222. The idea, as you say, is to "future proof" for HD tvs, to avoid the customer calling back when they install a HD television at TV2 and want HD there, requiring to then do a pair of 211s to replace that 222. Better to do it now when the tech is there.
Right now, for most cases, it's not forcing upgrades unless the customer needs a tech out for something. Then, it's forcing the upgrade. The cust may be forced to move to HD equipment, but they're not forced to add HD to the account, and if they are, they can remove the HD code after the install.