It is a downgrade. The whole post sounded like a downgrade since they felt the need to emphasize their commitment to experimentation.
I am one of the people affected by this since I was running a one-page website dyno and had pingdom keeping it out of sleep mode. This is what they are referring to as well in the last paragraph. I didn't know it was that many people doing this, though the solution for me would be a simple one: just allow me to serve static files.
I also used Pingdom to keep my Heroku apps alive, although I found it annoying having a separate free account on pingdom for every site and recently swapped over to StatusCake (https://www.statuscake.com).
Whilst you're right that it is a downgrade, it was clearly iffy to be using Heroku for free 24/7 hosting with essentially no downside on our end. I had no qualms however because it was just so expensive to move up to any other tier and it took so long for the Dynos to boot up.
Since they're adding the Hobbyist tier at only $7 I really don't mind this change and will happily swap over to it.
People wouldn't have been pinging their dynos to remain awake if it didn't take so long for them to spin back up. Know of any alternative places for projects that don't use a lot of resources?
IBM are also putting a lot of resources in to Bluemix which offers a 512MB dyno equivalent in their free tier, it doesn't run on AWS though. (https://console.ng.bluemix.net/pricing/)
If you've got a static files you could still serve it using Heroku free. Put cloudflare or another CDN in front of it and boom you've got 24 hours of fast responses. Though if it's a static site why do you need Heroku? Kind of like using a cannon to kill a mosquito.
A better static files offering is definitely something we've been asked for a few times. Near-term, if you put a CDN in front of a static app your dyno will wake up on release, fill the cache, and go to sleep. You shouldn't see much, if any difference for your apps at all.
Given the blog post calling people who use pingdoms freeloaders for using the service they advertised as free and changing offerings like this, there are other VPS hosts that don't pull a bait and switch after encouraging dependence that are cheaper.
I am one of the people affected by this since I was running a one-page website dyno and had pingdom keeping it out of sleep mode. This is what they are referring to as well in the last paragraph. I didn't know it was that many people doing this, though the solution for me would be a simple one: just allow me to serve static files.