For whatever it's worth: at Matasano we saw more Rails apps from startups than any other framework.
At Latacora that has changed dramatically; we see Django a lot, rarely Rails, but most commonly we see Go, Python, Node, and Java API servers with React frontends and minimal frameworks.
From my vantage point: Rails is still relevant and still a viable option for building new stuff, but it is less relevant than it used to be.
I see the same trend on Indeed.co.uk. In the last year or so there have consistently been about 40% more Django roles than Rails in London. At Angel.co, however, Rails is still more popular. I put this down to the general increase in Python adoption rather than anything specific to Django.
At Latacora that has changed dramatically; we see Django a lot, rarely Rails, but most commonly we see Go, Python, Node, and Java API servers with React frontends and minimal frameworks.
From my vantage point: Rails is still relevant and still a viable option for building new stuff, but it is less relevant than it used to be.