Apple brings two new 28 W processors to MacBook Pro with up to 32 GB of RAM and a 4 TB SSD; no 14.1-inch display upgrade though, while two Thunderbolt 3 models
Macbook RAM Upgrade – Fix My Mac | Repair/Replace/Revive your Mac
M1 Mac RAM and storage can be upgraded after purchase, but it's not easy - 9to5Mac
Is the 16-inch MacBook Pro User-Upgradable?
M1 Mac RAM and storage can be upgraded after purchase, but it's not easy - 9to5Mac
MacBook Pro Silicon RAM and SSD Upgrades: EveryMac.com