This is a great idea! Exactly what I was also thinking and started working on a side-project. Currently the project can create summaries like this [1].

Since HN Homepage stories change throughtout the day, I thought it is better to create the Newsletter based on https://news.ycombinator.com/front

So, you are getting the news a day late, but it will capture the top stories for that day. The newsletter will have high-level summary for each post and a link to get the details for that story from a static site.

[1] - https://www.hackerneue.com/item?id=43597782