It's supported, yes. Including Application-Aware.
https://helpcenter.veeam.com/docs/backup/vsphere/platform_support.html?ver=120

If you check here no it is not - Veeam Backup & Replication 12.3 Release Notes yes this is 12.3 but 12.1 does not support it either.

My bad I was thinking install on Win2008.  Apologies.

Hi ​@TonyHalligan -

As long as the vitual platform you’re using supports that version, Veeam supports it...yes.

But is that not just 12.0 -- 12.1 they removed it.

Chris - where do you see in the Notes that Veeam doesn’t support 2008 as source VMs (guest OS) to backup? As long as the hypervisor version one is using still supports it, Veeam does.

https://helpcenter.veeam.com/rn/veeam_backup_12_3_release_notes.html#system-requirements--vsphere-virtual-machines-os

Looks like the only thing not supported from what I could find in there were SQL transaction logs.

Oh..I now see you updated your post 😉

Yes I misread the OP my bad. 😋

ok, so…..when we say not supported, does it mean the Veeam VBR will not onboard 2K8 VM’s, or does it mean Veeam support will not/cannot assist with any issues…?

Nope everything is good.  Veeam will back them up and support will assist.  They may ask why you have an older OS but other than that you are good.