In a way, Apple have tied their own hands by making the M1 non-upgradable. They have to continue supporting it for years, which means they are somewhat constrained by their own decision to release an 8Gb base version.
OS X had a minimum RAM requirement of 2GB since OS X Lion. It took 8 years for them to up the minimum RAM to 4GB. Even if they double it quicker for some reason this time around and 8GB becomes the minimum (when was the last time they actually sold a machine with 4GB base RAM?) - they'd have to increase the requirement again before it becomes an issue. The machines will be constrained by the M1 processor long before that.