I'm sure that there'll be a 128GB option for the J105 ATV5. You have to take into consideration the temporary downloading of a 3+ hour film at 4K HDR HEVC along with the beautiful new 4K HDR Screensavers and 4K HDR games that will appear for it. 128GB is going to seem a minimum with all of that![]()
The current AppleTV doesn't [currently] use local storage for movies, only the RAM for a N second buffer (there's no "download" implementation in tvOS). Games and other non-music/movies/TV content, yeah, that is / can be stored locally, I guess it's possible they might have some concern over the existing 64GB max.