First, just to avoid confusion, the post linked to this HN article is just about the classic recursive resolver model. That's the scope of what is being experimented with actively.

Second, the notion of resolverless dns (where dns records are obtained from somewhere other than your recursive resolver) is indeed something DoH contemplates but does not yet allow. That's because issues around tracking, correctness, and attacks haven't been fully explored. So unsolicited DNS is interesting but its not something any browser would accept yet.

There are some other opinions on how HTTPS matches the needs of DNS here: https://bitsup.blogspot.com/2018/05/the-benefits-of-https-fo...