Berkeley Lab IT will be releasing the block on Big Sur for macOS. IT initiated the block to address software incompatibilities, more specifically with the Lab’s anti-virus software Sophos. Those issues can now be resolved by upgrading your Sophos client with the latest version from our Sophos server. For further information and other related postings regarding Big Sur, see:

Installing Sophos on Big Sur Upgrade

Installing Sophos Central v10.0.2 on Big Sur with M1 chipset

What Works and Doesn't Work Running Big Sur and Latest Mac Hardware