This is correct. The first step was removing varnish (which happened a few years ago).
Now, Heroku is hoping to get $7/month from many of the freeloaders. I highly doubt this would make sense if Heroku planned to grandfather anyone.
This was removed for architectural reasons. It brought a lot of downtime to the platform and didn't help speed all that much. It's better and faster to cache this type of content with a CDN anyway.
This is correct. The first step was removing varnish (which happened a few years ago).
Now, Heroku is hoping to get $7/month from many of the freeloaders. I highly doubt this would make sense if Heroku planned to grandfather anyone.