Moderator: Hawaii-based airlines & Hawai'i forums
Join Date: Mar 2003
Location: Ka ʻĀpala Nui, Nuioka
Programs: NEXUS/Global Entry, Delta, United, Hyatt, IHG, Marriott, and Hertz
Posts: 18,043
UA eliminated special meals for most domestic flights a few months ago, but I am fairly certain they still exist for Transpac and Trans-Atlantic flights, even in Y.
If this is so, I suspect this is one of many bugs related to the system integration and if prior experience is of any help, you should call UA to confirm the meal at least 24 hours before departure.
It may be prudent for you to bring some extra snacks with you "just in case."