Why go anywhere else when you are the number 1mim everything the factory does? https://www.racetrackmasters.com/2022/07/20/rea-extends-contract-with-kawasaki-up-to-2024/
Winning one championship is fantastic but six is even better, a happy unbroken format is a happy rider for the season and yes he should've tested himself with a different brand before he retired if it could win the title of course.
I think he's thinking of life after racing, so being a life long Kawasaki employee, certainly establishing a semi-works Kawasaki MX programme and who knows maybe running a roads team. Arguably it's too late for him to establish that sort of brand loyalty with Ducati. Some say he had that Loyalty at Honda, but he didn't. Honda's loyalty extends to not quite letting the door hit you on the arse on the way out!!! I think the racing has been good in WSBK this year but they HAVE to change the commentary team, it's shocking