I see a paradox here. When we ask why they won't give phase 1 cars OPD or other software enhancements, the answer is that they want to maintain the differential and they want people to buy new cars, rather than making the ones they have better so they stick with them. I feel this is illogical.
Phase 1 cars are no longer being made, so there's nothing in it for MG to "maintain the differential" with phase 2 cars. But more importantly, when people come to consider buying a new car, brand loyalty is quite an uncommon phenomenon these days. What on earth makes MG think they're on the receiving end of it? If owners decide to change, there's every likelihood they'll go for another manufacturer. In particular, if an owner feels they haven't been treated well by MG, they're far more likely to go to another manufacturer.
Imagine if MG had a business model that said, if you have an early model then we'll sell you the upgrades if you want them. OPD for how much? Once the bug-fix stage of the infotainment upgrades is passed (arguably R33 and R59 are how the cars should be) they could charge for better upgrades to that. They'd make money, and owners would be happy because they could have the upgrades they want. A happy owner is more likely to stick with the brand.
But as it is now, with the attitude that your car stays on the software it was handed over to you with, and you have to make a fuss and complain like stink to get any upgrades, and that certain enhancements will never be allowed for your car, we can see the result with discontented owners contemplating a different make for their next car. Prices are getting more reasonable across the board and MG isn't quite the standout it was 18 months ago.