I have heard that all the factions in the Age of Sigmar will get an updated battletome to bring them up to date and it appears the Sylvaneth are next. This goes along with that and some of the more obvious things.... like a new Endless Spell revealed today.
Games Workshop very much confirming the book is coming.....
Spikey Bits is saying this... seems reasonable, but as always add salt.
https://spikeybits.com/2019/05/gw-confirms-full-sylvaneth-release-imminent.html
Multiple industry insiders have mentioned that big A and the Sylvaneth are coming very soon. Here’s what they said may be on the way:
New Battletome update over to AoS 2.0
There own dedicate Terrain piece (not the rebranded tree stands from Warhammer Fantasy)
Warscroll Cards in the new format
Branded Tree Dice
One or two new character models.
Release as early as May
