It was expected that the NTA would tender part of Irish Rail's operation in 2019 anyway. Many countries have done this already, plenty of railways in Germany operating under contracts and the service works.
This is not privatisation
Multiple major railway operators have looked at Ireland already and given the poor operating standards of Irish Rail its only a matter of time before they get replaced.
Cant wait until these guys tenders for the Dublin commuter belt
https://en.wikipedia.org/wiki/MTR