Doubt I am adding anything that has not been said already. We were in the exact same situation a few years back, so I emailed the lady who was in charge (of spouses tickets?) and asked about bringing our son because of nursing.
While it is hard to read tone in an email, I interpreted her response as how-dare-you-even-ask NO.* Something to the effect of it is a very formal event and children were not welcome. So spare yourself the embarrassment of asking.

My parents hung out in hotel room with kiddos and we were first to gracefully depart the dinner so we could get back on nursing schedule.

Glad my wife got to go. It meant a lot more to her than it did to me.

*I did not press-to-test this as a newhire but probably would today. As referenced earlier, as diverse and accommodating as Delta enjoys parading the corporate culture, and with stories of at least one female trying to pump in the cockpit, you'd expect their response would have been different, right? I'll leave it at that...