The old feature was called "My Feed" and you are correct - it was very useful as an alert for available shows users were following.
Although Roku asserts My Feed was replaced by the "Save List", basically just more accurate to say that the My Feed feature was removed. In Roku's defense, I think some of the channel partners were not too diligent in providing accurate info/active participation for the My Feed and became a little unreliable for some users.
Basically, you now have to manually check your Save List (like you are doing) occassionally to see if your content is now available to watch.
I tried a couple of different mobile apps to see if I could find a suitable replacement for My Feed but didn't come across any that I would use or recommend. Most of the available apps seemed to just want to collect and track your information for marketing purposes. (I have seperate emails just for spam and testing apps/OS and just got flooded during that time.)
Roku Community Streaming Expert
Just another Roku user... I am not a Roku employee.
Insignia RokuTV, Ultra 4660x, Premiere+ 3921, Express 4k+ 3941