$wpdb:insert, more arguements in $format array than in $data

I think you’re assuming this is intentional, it’s probably just a bug in the theme, what it’s stating is the 5th parameter is a string, but there is no 5th parameter so it’s ignored.

The most likely reason is that during development a 5th entry was removed and the author forgot to update the second array, or that they accidentally duplicated a line