I had been looking for an RSS feed for Signal’s blog for quite some time and I finally found it.
For some reason there’s no link to it anywhere but there is actually one!
The RSS feed is actually “advertised” in the HTML source of the Signal blog:
<link rel="alternate" type="application/rss+xml" title="RSS Feed" href="/blog/rss.xml" />
Sadly, most browsers don’t show this metadata to users anymore. The Firefox extension Awesome RSS changes that.
That’s how I found it, by searching in the HTML inspector of FF