The "What to Watch" feature was supposed to be a Roku OS 11 feature.
I think Roku sometimes releases these features early to user devices for testing (which may be why you saw it on 10.5) and then removes it and will again release it in a build specific for your device.
My devices had the "Save List" hit them early, then it was removed for awhile after I started using it, and then reappeared a month or two later in an update (I think OS 10.0 or 10.5). There have been other features specific to RokuTVs that I remember encountering also.
The above is my best guess, I have no firsthand/inside knowledge. It will eventually return though in some update build of OS 11. It is a bit irritating though when this happens.
Roku Community Streaming Expert
Just another Roku user... I am not a Roku employee.
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