Some info from KTAC page:
Q- What happens if I pay off my contract with Kubota Credit Corporation, U.S.A. early?
Your insurance through KTAC Insurance Agency will cancel at the time of pay off and the unused portion is applied to your current balance. You can choose to purchase a new policy at this time by contacting a representative at 800-348-5802.
Q- Can I purchase insurance through KTAC Insurance Agency if I pay cash for my equipment?
Yes! The Kubota-Endorsed Insurance is available for anyone owning Kubota equipment.
I couldn't find anything about replacement though.