the only way this could be done without a massive public fallout of customers that bought the worse version, and without pissing off developers for now having to target yet another set of hardware, would be if Microsoft basically spends millions of dollars replacing every single Xbox Series S on the market with the new model.
meaning sending out messages to owners of the Series S to send in their console to receive this new hardware refresh, telling them that their console will not be supported anymore after a certain period of time.
because if they simply send out yet another SKU with yet another performance profile, it will turn into a shitty experience for owners of the original model. We already see the Series S being only supported with bare minimum features by many devs, now imagine in there are 2 separate Series S systems.
the only way to solve this issue without actually requiring Developers to do anything would be to basically not give development hardware a dedicated profile for this new version, so that they only ever target the low spec version. this would in turn mean that this higher spec version would be using the additional hardware grunt to simply run Series S software more stable and push dynamic resolutions higher.
this would still piss off a lot of customers that bought the original model of course, but it would at least mean that developers don't have to do anything additionally to support it.
the One S was like that in a very tiny fashion. the One S has about 10% more GPU power than the base Xbox One, but it was only really ever used to run Xbox One games a tiny bit more stable (see the FPS increase in Project Cars for example). Some titles actually support 1440p on the One S (like Doom 64) but that has not really anything to do with the GPU being better but with it actually supporting output above 1080p