The only reason to to do it would be to compete with a peer insurance company that is already doing it, resulting in less profit for both parties. The optimal strategy from the insurance profit perspective is to ban any DNA based cost saving measures for all insurance companies.
On the feasibility point, if this use case is entirely infeasible I don't know what all the hand-wringing on this board is about!
(Slightly longer answer: I don’t have the funds to match what someone is likely to pay for this data, but if I bought it and gave it to you for free, and also gave you all the inpatient hospital discharge abstracts in the US in a matchable form, plus whatever health data you want, plus family relationships, plus a budget for 100 PhDs, product managers, and marketing people for 5 years you couldn’t turn it into a viable product. (Indeed that is literally what 23andme tried to do for years!))