While I think that could happen, what difference does it make? Either way the 4 and 6 will have 2 types of trains regardless. I dunno how different the parts on the R142s are compared to the R142As, but why not just keep all the R62As together? As for the R142As, I always thought they could swap the remaining R142As on the 6 to the 4 for the R142s since the ones on the 6 seem like they are so 'poorly maintained' (bucking issues).
You make the stuff about the politicians overblown. Now one gives a damn what they think. If the trains have adequate a/c for summer and heat for winter, then what's the fuss about? At least they can see the giant rollsign showing what train is coming (6)/<6> instead of looking at the small digital sign on top.