For me the Occam's razor is, the old liberal position became unsustainable for them and they decided to change the policy by adjusting the wording. Anything else seems splitting hairs to me. If they enforce it for existing owners, I wager it could be argued bait and switch, which is why I doubt Tesla will try to enforce it beyond letters. I do sympathize for Tesla, but the original sales pitch for the Supercharger was their own doing. Re-writing history doesn't seem comfortable for myself either, which I think it reeks a bit of.
Hopefully it will remain a soft issue, instead of hard policy, so we can chalk the episode up to nothing much. One can expect, though, it to become a hard policy for Model 3 and beyond (and perhaps new Model S sales etc.), if "free" Supercharging is offered at all for those cars. But for new sales that is OK of course. For new sales Tesla can make any new sales pitch they want.
The splitting hairs -- I think that's what defenders of local charging have been doing. All along. I think Tesla has been making every effort to stay with the concept of 'free, forever'. I think Tesla has been very classy by trying to avoid limiting statements, and just expecting ... hoping? ... that the vast majority of people will use the superchargers as intended (long distance travel to remove the "EV stigma", and now added high-congestion city dwellers with no other charging option). Even Elon's comment yesterday was along the lines of "we don't really want to have to do this, but if someone is abusing the privilege then we'll try to softly encourage them not to" (i.e., start by writing a letter instead of spend hundreds of thousands in programming to find an automated power-reduction solution). And they'll see how that works and find other solutions from there, if they have to.
The OP's statement about being oversold, I just don't get that. Again, it's splitting hairs, parsing out the individual phrases and ignoring the overall context and intent. And yes, I meant in the previous paragraph to say "abusing the PRIVILEGE", from a societal perspective and Tesla's intent for the "free, forever".
Anyway, I also think as others have posted here that eventually, the OP's time will be worth more to him than the $100/month or whatever he'll be saving. I think his last numbered set of procedures, if you will, are reasonable in the short term, although they are outside of Tesla's intent. And Tesla will choose to handle that situation if and when it becomes important enough to spend resources on it. I'm not defending the OP's actions, but, the good part of it is, the OP is *thinking* about it. He's *aware* that there is or could be an issue. That's a big first step.