I've hear there have been CAD sculpts seen in the past 6 months for all of the aspects AND wraithguard, just dont know if they will be finecast or get broke out to plastic kits yet.

My newest batch of rumors here is coming from playtest notes, which are notoriously unreliable this far out form codex release, but they do indicate the direction being thought.

Also a bit more on the wave serpent. Couple things have been tried on the shield, from 4+ invul on any penetrating hit, to something similar to the necron shield where the armor drops after its penetrated once. The rumors are all over the board there, but one thing is certain that mechanic is being looked at and will lkely work differently in the final codex.

As far as the phoenix lords go, they are rumored to provide a table wide buff to their aspect units while on the board. For instance Karandras is rumored to grant +1A or +1S to Scorpions.