Tomorrow stream is most likely about Beta and release date. "New" stuff we probably hear about will be:
- pre-patch content
- world quests/emissary and Mythic+ changes (I don't think they'll touch raid or PVP structure at all)
- Maw zone mechanics
For sure I wouldn't expect any Covenants redesign. We all fear that they'll be completely unbalanced, but no number tuning has been done yet, it's late Beta territory. Also SL are so deep into development it's too late for fundamental changes.
Funny thing, I prefer that they COMPLETELY screw up balance on Beta than smaller (but visible) gap. It would force Blizzard to make easy swap for Covenants. Don't want to argue about it, I just prefer "on the fly" design (like D3 and WoW new talents) than "meaningful choice" (like D2 and WoW old talents).
And of course I don't want people running with Kyrian chest and Necro wings, so Necro transmog should be disabled on Kyrian character etc.
People see what they want to see.