I think reintroducing wolves could help biodiversity in Ireland. There was an example where wolves were re-introduced to Yellowstone Park. Initially people were concerned as they were worried that the wolves would reduce the number of deers but actually the opposite happened.
The wolves scared the deer away from river bank which meant that the plants were able to flourish again. More plants meant more food for deer and even though the wolves did eat some deer there were more deer. This meant the wolves helped the biodiversity.
Now, this might not happened in Ireland but if it is done slowly and managed correctly it could be a good thing.