I don’t think it’s either. The recent press information about Brennan’s, that I’ve seen, makes no mention of a production brewery. And I very much doubt YellowBelly will try and start a new one.
I found an article about that new to be built brewery in Glasnevin for a number of pubs in Dublin. Reminds me of the club brewery for the working men’s clubs in Britain.
Not sure if this counts but Proiry Brewery have installed a new kit so presumably should have beer back out soon. Untappd showing no check-ins for them since June 2021.
As mentioned by Lugh at the AGM: Blarney Brewing is being set up, with Get ‘Er Brewed supplying a Brewiks kit. They’re on Instagram: https://www.instagram.com/blarneybrewingco