It’s unlikely your insurance will cover wood rot caused by natural wear and tear. Some of the main causes of exterior wood rot are having bushes too close to your siding and/or living in a rainy climate. Over time, this can create ideal conditions for wet wood rot.
That said, standard home insurance might cover wood rot in certain covered perils, such as damage caused by:
Wood rot takes time to cause damage, so if an undetected leak caused by one of the perils listed in your policy has caused wood rot, you may be able to file a claim successfully. Also, keep in mind that most homeowner policies do not cover flooding and storm surge damage and this is a separate issue.
Best of luck with your home improvements!