As far as I can tell pandoc supports dpub-aria in output since #4213 was merged. But its possible there was a regression
For some reason my documents do not have doc-biblioentry roles on the entries in the bibliography. Each child of the div which has the role "doc-bibliography" should have the role "doc-biblioentry". In the examples the roles are correct.
I put together I minimum working example in a github repo since there are two files involved. The README explains the issue and has my system info. The html output shows the output with the missing role.