I saw a couple of related questions about Oracle VM Server for SPARC 3.3 support recently:
Are T7 servers with Oracle VM Server for SPARC 3.3 supported in Ops Center?
Yep. You can take a look at the Certified Systems Matrix to see the full list of supported systems.
What if I want to downgrade systems to Oracle VM Server for SPARC 3.2?
That's not something we've tested or certified.
Are live migration and automatic recovery supported for OVMSS 3.3?