Hey Chris,
If by “expires” you just mean that when an event passes from “will happen” to “has happened”, and becomes a “Past Event”, then there are not any meta fields on the event that will change just because of that fact.
And just to share it in case you haven’t seen it already, and it might be useful for your project, we have a list and description of all meta fields for Events, Venues, and Organizers here โ https://theeventscalendar.com/knowledgebase/wordpress-post-meta-data/
Might be handy ๐
I hope this info helps โย let me know if it does or if you have any other questions or concerns.
Cheers,
George