I don't remember where I read how the designator of the procedures are determined, but I am pretty sure that if you see RNAV (GNSS) you require GNSS.

In the 10-2 in FRA it says RNAV (GPS). This looks like the same.

Micro,

I don't think that is right... As the US used the (gps) to show that a certain approach could be flown as a gps overlay... So this would mean it had dual meanings.

Eg. NDB 23 (gps)

PT6A

Plus it's not the title of the plate. It refers to the note.
It means aircraft who are RNAV compliant or can fly RNAV procedures using a standalone GPS must use these procedures.