1. Is there some nuance in the code i'm missing that will make it be short and readable instead of adding ugly hacks to get map to read that as a code block instead of a hash reference?

The easiest/cleanest way seems to be to add parens around the contents... $two->( map { (anda => $_) } @one );.

2. Is anyone else having this problem? Or is it just me?

Your code broke for me as well

3. Assuming it's standard behavior from 5.6.1, is it fixed in 5.8?

I get the same results from 5.8.0.