Oh so dependent on the actual model not ThinkPads themselves.

As far as I've seen nearly all of them have Soldered ram now. Can you point to some that don't?

Some of the latest models in the "classic" lines with one or more RAM slots: P14s Gen 2 AMD/Intel (a.k.a. T14 Gen 2 AMD/Intel); T15 Gen 2 / P15s Gen 2; P15 Gen 2; T15p Gen 2; P1 Gen 4; X1 Extreme Gen 4. Plus some of the slightly more "budget" ones like L14 Gen 2 AMD/Intel and E14 Gen 3 AMD.

Tip: search "<model name> psref" to quickly get to a PDF with specifications.