Legacy vs 4th gen Channels

I have both a Legacy Tablo (2.2.58) and a 4th gen Tablo (2.2.57).

There is a difference in the number of virtual channel on the devices. An example; CNN is on the 4th gen, but no on the Legacy. Why?

Hello,

CNN Headlines and CNN Originals are online streaming channels avalible to our 4th Gen apps. While Legacy can access some of these channels through the Legacy Transition not all of them are available. This is because legacy devices cannot support streams that use HTTPS technology.

Ah, would that also explain the absence of Anime HIDIVE?

It would indeed.

You can find the full list of streaming channels and which ones will work on legacy models, here.