SOLVED: The function called $user_id first and was assigning it to my $usermeta variable. I ended up using get_usermeta with $user_id as the reference.
UPDATE: It looks like $usermeta is getting the string that should go in ‘meta_key’ and the array of data that would go in ‘meta_value’, but it is not actually doing the insert. Is this something goofy with a validation against xprofile fields?
Update: Looks like the field needs to exist in wp_bp_xprofile_fields. I manually added it, but it would be nice to figure out how to do it dynamically.