I would see no issue here other than specific policy limitations, which per OP are not restrictors to re-assignment according to Irish Life. re-assignment of policies is a minor issue in the process of mortgage transfers and the security Depts of all banks are well used to dealing with them.
I think that's quite clear. What seems to be less clear is whether there are likely to be any specific policy limitations.
From your own experience, would you agree with Monbretia that it is very unlikely that any mortgage protection policy written in the last 10-15 years was arranged as part of a block policy?