Why wouldn’t they just take the old oil and put it in a new bottle to maximize profit with zero effort?
I highly doubt that there is any effort required on Yamaha's behalf other than package labeling. They are engineers and designers, not petroleum chemists. They do not manufacture their lubricants but job it out to the lowest bidder that can meet the engineering specifications. They may specify viscosity, conventional vs synthetic, additives, foaming properties, temperature coefficients, chemical oxidative stability, lubricity/additives etc., but I would bet dollars to doughnuts that this is not a unique Yamaha product - far more likely a rebranded off-the-shelf (and highly marked up price) product from Mobil1, Shell, Castrol, Lucas etc. As said, it certainly won't hurt to use it and in the big scheme of things, the cost per mile is still cheap (although far more than the store brand I use). Do what you are comfortable doing, but don't suggest I am making a big mistake with my choices. I will, perhaps, listen once you have a half million kilometers on your bike(s) without failure and my rear drive goes up in flames tomorrow.