I should add, technically if you had an older calibration, it would update your transmission tune.
There are 10 base revisions that Ford has made over the years. An early 2020 vs a new 2023 actually has quite a bit different transmission side, including shift points and pressures.
Saying there's no changes, I'm comparing the latest 2022 calibration to the Ford Performance calibration.
If you had a car made before roughly early 22MY (so Oct'ish 2021), you actually do get what Ford's advertising in optimized shift points and the like.. The only thing is, its optimized to what you'd get on a new 22 or 23. (Also technically there's solenoid changes in the valve body from the early to later cars, but those aren't gonna change this).
You also get a fresh adaptive reset, which can definitely change how your car feels compared to even when you drove it brand new.
I understand your car "never felt like this even brand new", but adaptive learning on a new transmission and learning on an already driven on transmission will not necessarily learn the same shift parameters for the same wear. How Ford's adaptive algorithm work is it targets some set times and rates, but not necessarily an optimal setting to produce that time and rate, so when and how it learns it can change things. It's also why most dealerships first reaction to shifting problems is to reset them (because that's what Ford tells them to do in the shop guide!).
Basically what you're getting is the latest transmission calibration and a fresh adaptive learn. Both are positives and will change how the trans feels and operates, but its not like Ford Performance tune put Mustang drag mode shifting parameters in the transmission suddenly to target if you get what I'm saying.