Unmentioned in the Sneak Peek is Raid formations
Even more than Raid Formations itself, is the planned PUBLIC BETA test of Raid Formations. It is such a potentially huge change they actually want data en masse to see if any heroes in certain configurations become drastically overpowered or not before they commit to implementing it. 
And it became much better IMO from the first round beta testing to the second round.
- All-New Hero Upgrades : If this is like “artifacts / weapons” (a second slot of troops with different bonuses) similar to other Match-3 games, I’d be for it as it. Otherwise, please no more tiers or levels for heroes.
- More Quality of Life changes : Friendly Raids are going to be GREAT!.. At the top of my list otherwise: Improving the in-game chat would be #1. Looking at you, line return, colors and emojis. Filters for the roster and revamping the common Quests also seem overdue.
Also, I don’t know if this can be said enough, but players need a way to reset heroes to recover Ascension Materials as heroes get nerfed or otherwise obsoleted over time.