No idea to be honest. Did some searching around the net and there is loads of guides on doing this in many different languages, so I imagine this practice is pretty widespread, since it was released in India. Worst they would do is cancel your subscription I reckon.
Edit: Quick update after using it:
1) Youtube main app - as you would expect, no ads, picture in picture enabled and background play. All suggestions and searches are as normal.
2) Youtube music app - Top charts, Todays hits, Featured artists and other playlists are Indian oriented. The section where you pick Artists you like is also the same, with a few western artists in it. If you search 90s hits, for example a lot of the playlists it finds are Indian.
3) GPM app - Similar to 2).
No big deal as I imagine all the global content is there if you search, it's just not great for discovery and suggestions (although maybe it will change as you use the apps more).
I primarily wanted the extra Youtube main app functions so still a bargain for me! I still get a music selection similar to spotify/apple music, I just need to search a bit to find the content I want.
rp2000