Under Settings->Editor theme->Editor tab, I previously had set the 2 $foo matched highlighted variables to be pink text on dark blue background, but that setting is no longer available as far as I can see, and in the editor itself the matched variables are no longer highlighted. Is there a way to get it back?

I installed 15010 at office and home and both installations had the same issue with matched variables not highlighted, but this morning it unexpectedly started working at my office. Not sure what switched it on. Still no way to change it in the Settings but I'm not too fussed about that. I haven't checked at home yet.

I think that in the beginning the built-in parser was busy parsing your project(s) and you didn't give it a chance to parse currently open file to highlight the variables.
As soon as parser has finished, editor started showing them.

Thanks, the project is quite big so that sounds very likely, and it's also now working on my home installation. I think what threw me was that it hadn't happened with previous upgrades but in future I'll make sure to let it parse the project completely.