no the hidden tracks are not hidden on the mc mix. And for me it is better that way as I want to have access on the hidden tracks with the mc mix. For the purpose you mention, havin drum tracks only, or vocals only… I do that way…
I create a group track for each “familly” of tracks I want this type of access, I place this track before the audio tracks assigned to it. I lock these groups on the first mc mix (you can lock and choose the assignations on the mc mix). when selecting this group on the left mc mix and hiting the “next track” button on my faderport, the second mc mix display all the tracks of this group (the 8 first)… very fast and usefull. This is the way I do it.
Another way is to create “templates” in the mc mix software and saving them. Then you can recall them, but it is not very fast. So I save only my template with the assignation of my locked groups and tracks on the left mc mix. And when I open a cubase session it is recalled instantly.