Python2 is EOL at the end of this year, one of the few remaining things that uses python2 is perf. See this bugzilla entry from Redhat: https://bugzilla.redhat.com/show_bug.cgi?id=1536656
This may not happen for 2.8 since it'll likely be the kernel.org developers who work on removing any python2 dependencies.
From the RH bug, it looks like the kernel supports py3 now so we just need to change how the recipe builds.
I'm seeing some intermittent and unexplained packaging errors with the py3 switch done. But am testing this on more targets now and should have it sorted in M3.
PoC is done. under test now.
Fixed in oe-core 584af667e0000129bcb5c9e8108485f2f6590eaf.