This is the standard practice in some of their Scandanavian banks(as they are owned by Danske Bank) and some of their new branches they opened over the last 2 years are already cashless. Reality is that processing cash costs is expensive with higher insurance costs for the banks, as well as security operational costs and it's a business they've decided they don't want or need to be in.
I think they've accepted they'll loose customers over this, but if the cost savings outweigh that, then it may make sense to them
There is also a Scandanevian view that we are too paper orientated in Ireland and that we would be better moving to electronic banking. This seems to be their step towards it