Earlier quoted context omitted.
The soldered RAM is surprising for Framework, and doubly surprising for being so in a form-factor that usually doesn't have soldered RAM. Similar to what other commenters have expressed, it just seems like they shouldn't have built this product if they couldn't figure out the soldered RAM bit.
Apparently this is due to signal integrity. AMD says swappable RAM is not possible. Source: LinusTechTips video.
I guess they'd claim it is only the MAX AMD procs which force soldered RAM, but since they could as well have used a non-MAX chip (and correspondingly reduce the price) this just shows how much of this is an arbitrary, and therefore questionable, decision from Framework rather than any restriction AMD sets.