Honestly, this used to be the case, but the past couple of years Lenovo is going back to their old ways of sub-par upgradability, and sub-sub-par support across models for Linux. I believe the P-series is the current most compatible line.
You might want to consider getting a slightly older refurb you KNOW is very compatible versus a newer one, because it’s a crapshoot. Make sure to avoid any models with soldered memory (they specify on their site), and if you’re buying a modern AMD model, do some research and make sure they haven’t crippled any features in the BIOS.
If you’re not completely sold on Lenovo, look at getting a Framework laptop. It’s the most upgradable and repairable laptop of any kind out there.they also just started an outlet online store where they are selling last-gen models at deep discounts that you could upgrade to current Gen when the time comes.