can I upgrade from big sure to Monterey in Mac Pro 2019 with 4 thunderbolt

Tend to agree with giving Monterey some time to be debugged before upgrading. Especially if the machine is a Production / Mission Critical computer.

Regardless - for that type of machine a Rescue Plan In-Place. This comprises having 3 Backups using 2 methods and 1 Off Site incase of Theft, Loss or Natural Disasters. A Time Machine Backup  is very useful and can be used to Revert to Previous Working macOS. For addition purposes - two Tested Bootable Clones each to separate external drives. This is insurance incase the upgrades goes sideways. At least one Tested Clone and / or Time Machine Backup should be Off - Site

Do you really want to upgrade to macOS Monterey when they release it next week.

I'd give it a wide berth, Apples recent form in releasing OS and Safari updates leaves

a lot to be desired.

I'd give it until at least the first two point releases have been released.

Yes. When Apple finally releases it in the Mac App Store next week. Do a Time Machine backup before the upgrade, and do not reuse that Time Machine drive for any Monterey backup.

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