I'm doubtful that they will air TV ads. I remember there was only one commercial for the iPod touch 5th generation and the other iPods.iPod touch 5G had 16GB as base model, I believe that should be improved upon if they want to revitalize sales (the main question of this thread).
Of course it all may also depend on how good they will market it, will there be tv ads etc.
I wish that they would make a commercial that shows how the iPod touch can be used (for example, gaming, pictures, etc.). That would at least let people know that there is a new generation out there.