Native English speaker here. The sentence was definitely missing a word. I read it multiple times before I got it too. Your rewrite was easier to understand.
[only on HN] could [any state [that Gentoo was ever in]] be [reflected upon [as "just worked like a breeze"] unironically]_,_ and [I] mean [that] [in a fond, loving way]
[only on HN] could [any state [that Gentoo was ever in]] be [reflected upon [as "just worked like a breeze"] unironically]_,_ and [I] mean [that] [in a fond, loving way]