I know of no reason. Here we run production DSpace 5 and 6 instances
with PostgreSQL v14, and I use v14 for test and development with
DSpace 7.
I'll be trying out PostgreSQL v15 with DSpace when it's stabilized on
Gentoo, and I will be very much surprised if there are any
incompatibilities.
--
Mark H. Wood
Lead Technology Analyst
University Library
Indiana University - Purdue University Indianapolis
755 W. Michigan Street
Indianapolis, IN 46202
317-274-0749
www.ulib.iupui.edu