When parsing export foo=(bar), the array_assignment_list node has token value bar) instead of either bar or bar). This is also true if the list has multiple element, e.g. export foo=(bar baz) yields an array_assignment_list node with token value bar baz).
The underlying combined_word node(s) have the correct value(s) though, although the parentheses are not contained - I was expecting bash:LP or bash_LT nodes but maybe this is expected behavior ?