I don’t think the change to Live Components being only available in 2021 format was intentional. Thanks for pointing that out. I’ll check with the teams. Note that lots of people are out on vacation this week so I might not have any info until next week.
My understanding was that downloaded Live Components would be in v2020 format for the near term. Eventually, they will fall under our “current minus two” policy where we support the latest version and two versions back.