array_filter takes (arr, callback)
https://www.php.net/manual/en/function.array-filter.php
array_map takes (callback, arr)
One function works against a single element, whereas the other works against multiple. In that case, the parameter order is more meaningful. You can use array_walk if you want (arr, callback), but that only works against a single array -- similarly to array_filter.
Optionally with a better language you know what order params as passed (array_map / array_filter), but in PHP its an coin toss.
This feels very bolted on and not suited for the stdlib at all.
PHP devs should instead FIRST focus on full unicode support (no, the mb_real_uppercase wont do), and only then focus on a new namespaced stdlib with better design.