What to expect from insurance company when I have hail damage to my roof and I have replacement value coverage?

Insurance only covers the cost of getting you a roof exactly equal to the one that you had previously. If the original roof did not have a vent, and you want a vent, you have to pay for the vent yourself; the insurance does not pay for it. If the previous roof did not have a warranty or the warranty had already expired, then the insurance does not have to get you a roof that includes a warranty, and it certainly does not have to pay for a vent to keep the warranty from being invalidated. It pays only what is necessary for you to have what you had before the hail: a roof with no vent and no valid warranty. Anything additional expense for you to have anything that you did not already have, like a valid warranty or a vent, is not covered by insurance.