I agree, I think the 13 is going to be more akin to the equivalent of an S model in previous years. Less than one year since the X was released, Apple discontinued that for the XS so your right.
Possibly labelling the 13 as an 'S' model may not do it proper justice as it has hardware upgrades with the 13 cameras and smaller notch etc. plus making it marginally thicker for the bigger battery (which is a key seller). On the software side, the 120mHz Pro Motion display on the software side is a big jump for the refresh rate and will be enough for some to upgrade along with improved video etc. So maybe more of a hardware/software leap forward than the old 'S' versions. Lets see tonight! I totally get why people would wait for the 14 though, especially given those leaked renders!