You are right. The EnterpriseDB Enterprise Edition is not listed in the platform support guide.
As per the internal discussions , below is the conclusion:
There are additional tools, changes, etc. that have been provided by Enterprise DB. The Pega 7 Platform software might run on this, but it has not been tested recently. (We tested it a number of versions ago, and there was a problem. This problem may or may not have been fixed - we have not tested it recently.) Therefore, we state that as it hasn't been tested, the Enterprise Edition is not officially supported.
I have sent you a email regarding this. Hope that will help.