Comment # 2 on bug 1202126 from Kilian Hanich

(In reply to Richard Brown from comment #1)
> all supported MicroOS system roles have pkexec if they need it

I tested if it's missing by installing MicroOS (choosing the Gnome Desktop role
in the installer), after logging in doing "sudo transactional-update pkg in
gparted", then rebooted. pkexec was not installed.

So, if you mean with "supported system roles" all which are not RC (or ealier)
then this is the case.

If you mean "all roles selectable in the installer", then no.