Downgrading 2020 iMac to Catalina later?

[minvoyager]

I'm aware of the principle that you cannot downgrade a Mac to an macOS below which it shipped.

For the 2020 iMac that is currently shipping with Catalina, and later will ship with Big Sur, if I buy a 2020 iMac later which comes with Big Sur, will I be able to downgrade it to Catalina?

 

[Taz Mangus]

Yes you will be able to install Catalina on the 2020 iMac later. It was much the same case with the 2019 iMac when it first came out installed with Mojave 10.14.4 and later Catalina.