So, it's helpful to look at this in the context of: it's common in certain western states (UT and NV do this too, not just AZ), when a route ends at an interchange, for state maintenance to continue a few hundred feet past the interchange so as to include any turning lanes, signal detection hardware, etc. And this holds whether or not there is another intersection after those few hundred feet.
The general policy I've been following with UT, and will thus apply to AZ to for consistency, is to not map any of these dangling ends unless there is
clear and non-conflicting signage indicating the route extends past the interchange.
In the case of AZ 79, the presence of
these TO signs (there's one on each approach) conflicts with the END sign, and there is nothing at the US 60 interchange itself indicating AZ 79 going both ways.
In the case of AZ 186,
this JUNCTION sign conflicts with the END sign, and as was previously indicated, signage from I-10 does not indicate AZ 186 going both directions.
Ergo, this looks like a no build on both to me.