This is the reason that you insure your rescue cat asap before they have clocked up a history
The insurance companies want our money , and the majority of cats come from a rescue environment now, or one of those sales etc that we dont talk about and therefore premiums are adjusted across the pet insurance market to allow for a percentage of high risk claims.
As more and more pet owners are taking out insurance very sensibly, the market grows and so does the pot of money to pay out claims. If you are insured by a company like AXA without any bothersome underwriters they are free to make business decisons based on actual facts as they have the stats, also on what their competitors are doing. They got burned by M&S a couple of years or so back and chucked them out, as many of us now with AXA know. Initially it took a while for premiums to calm down again after that but certainly this year they seem to have.
Every thing in insurance is a calculated risk both for those who give insuarance and those who purchase it.
However the message is to insure your cat because come the day you seriously need it, the years that you havent claimed are all suddenly justified and the cost probably still wouldnt pay the bill if you had saved it.