What do MacBook Pro 2020 model codes mean?

There’s no 2020 or 2021 model of the 16″ MacBook Pro currently. The 16″ MacBook Pro only exists as the Late 2019 model – there are no others.

The codes you have refer to various build-to-order variants. For example you can buy the 16″ model with 16 GB RAM, 32 GB or 64 GB RAM, there’s 3 different CPU models, 3 GPU variants, 5 SSD sizes, and so on.