Hi Manuel,
no, it's not actually 2 guitar modes, it's Guitar Mode 2. ( not unless you've heard about something in the upcoming upgrade that I'm not aware of haahaa)
It's an improvement Guitar Mode 1 functions. Guitar Mode 1 you could only have guitar mode 1 type notes, the strums, the fret noises etc.
Guitar Mode 2 you can now have a mix of Guitar Mode notes & normal midi notes in the same track. There's probably other improvements ( I really only have a basic understanding on how to use it,) but that's a really helpful one for me.