Yes - they, like all other Banks, want their interest to be noted on your buildings insurance policy and to hold details of your policy to know it's in force, the level of cover etc. Quite normal and typical for a Bank ... also covered in the terms and condicitons of your loan contracts, I expect. If memory serves, I've had this requst from them quite regularly, perhaps every year although maybe not quite that frequently ...
My letter seemed to suggest I only needed to send them a copy of the policy, if it had changed from the one I previously provided them with - other than to have renewed it, my own policy has not changed and Danske (well, eh, National Irish Bank) are noted on the policy so I've taken it that they don't need a copy of the current policy. No doubt they will contact me if they do want a copy