Hi there - yes I am scheduled for this evening's flight to DUB. I'll post a review here although to be clear I'm lucky enough to be at the front of the plane. My interactions with Aer Lingus on the phone suggested they had they ability to see seats (they told me the business cabin was 2x2 for example). I can see my seat number on the new plane in the booking but not the configuration as you would with a normal Aer Lingus operated flight. I would imagine the layout is not identical but I would hope they would prioritise you with your infant and bulkhead requirement.
For me - the online checkin process worked (although it all struggled a little) but there was no opportunity to view or change seats. I can only recommend calling again and seeing if you get a different agent to be more helpful - failing that, get there early! Happy trails to you and the little one :-)