Hi Yoshi,
I currently have the same especifications that you mencioned (vRA 7.6) and actually we are using RHEL 8 for deploys.
vRA use vCenter (agents) and VMware tools for several actions like reconfigure, power off, so that depends on your ESXI + GuesOS compatibility. Check the VMware compatibility guide to be sure (https://www.vmware.com/resources/compatibility/search.php?deviceCategory=software&testConfig=16).
In my case I also did the following test for you.
1 - Deploy my blueprint and check it in vCenter (VMware tools are guest managed).
2 - Test a day2 action (reconfigure) --> OK.
The only problem that we faced was related with vCenter customization specs and fortunately was solved installing the completed perl package on the template VM but it depends how you are configuring your infraestructure (custom specs, ansible, cloud init, etc).
Hope it helps.
https://www.linkedin.com/in/eric-daniel-cano-394022117/