Thanks for the explanation of the dry rot condition and it was definitely cracked of the tire case. No, she does not park in a tanning booth and pump ozone in but we did consider it.

The tread was worn out so I would have needed new tires anyway and I thought 15K was good longevity compared to mine and how I drive. She is much less aggressive on the gas and brakes than I am. I will mention this to the dealer next time I go in and yes this was the selling dealer. I have read about tires getting old on the shelf and have insisted on fresh rubber.
That is something everyone should become familiar with, tire manufacturing date codes on the sidewalls, and not just for motorcycles, but for any type of tires you buy. There are tons of old but never used tires sitting in dealerships and warehouses all over the country, and you don't want them. But I would be very surprised if the tires that came on that bike from the factory were old.
FYI, studies have been done by various interested parties including auto manufacturer's, and many now recommend that you do not use tires that are beyond 6 years from the manufacturing date.
Jerry