The real question is... what if the original Series S is no longer mandated in the middle of the generation? What if developers can choose to skip the console and only develop for higher grade Xbox consoles (Series X and whatever it is replacing the S). Wouldn't that destroy the concept of "generations" as we know it with respect to Microsoft/Xbox? Or would that be another GameBoy Color sort of situation where they will be counted as one system even though they're clearly not, because several late games will not be supported by the S in favor of the X and the S successor.
I mean the name "Series" itself is an implication that Microsoft might follow a "minimum requirement" model of sorts, making it a hybrid between traditional consoles and PC. Very high chance this is what they will do if Series S's small RAM proves problematic for the more ambitious future games.
This is one of the many reasons why Xbox is unpredictable to me. People have different ideas as to what constitutes a generation.
And maybe in future there won't be new model that replace the Series S, but instead the Series X will replace the Series S as the low budget model and there will be new more powerful up to date model which comes into the Series X place.
They can release as many consoles as they want. But if they drop support to soon for any fans won't be happy.