UPDATE: This thread is out-of-date and is no longer being updated.
As requested, I’m making a new thread with all the upcoming spoilers currently available in the game data (ending 23 October 2017).
So, more than ever, this information is fluid and ever-changing, up to and including Kingdoms coming out at different times or in different orders than planned. There are no promises that this list will be completely up-to-date with the latest changes to the in-game data. You have been warned.
I’m keeping the format from last time, but dropping the 8-star calendar.
Arcanes for Glory Calendar
06-12 Epic from Drifting Sands is Green/Brown (2 x Arcane Forest)
06-19 Epic from Divinion Fields is Blue/Green (2 x Arcane Swamp)
06-26 Rare and Ultra-Rare from Grosh-Nak are Brown/Yellow and Green/Red (Arcane Mountain, Arcane Beast)
07-03 Ultra-Rare from Darkstone is Blue/Brown (Arcane Shield)
07-10 Rare from Maugrim Woods is Green/Brown (Arcane Forest)
07-17 Ultra-Rare from Urskaya is Red/Purple (Arcane Dark)
07-24 Ultra-Rare from Silverglade is Red/Purple (Arcane Dark)
07-31 Common from Khaziel is Blue (Arcane Stoic)
08-07 Ultra-Rare and Common from Leonis Empire are Green/Yellow and Red (Arcane Light and Arcane Rage)
08-14 Epic from Forest of Thorns is Blue/Brown (2 x Arcane Shield)
08-21 Epic from Glacial Peaks is Brown/Red (2 x Arcane Lava)
08-28 Ultra-Rare from Suncrest is Red/Purple (Arcane Dark)
09-04 Epic from Zaejin is Blue/Purple (2 x Arcane Spirit)
09-11 Ultra-Rare from Urskaya is Green/Brown (Arcane Forest)
09-18 Epic from Merlantis is Blue/Yellow (2 x Arcane Blade)
10-02 Ultra-Rare and Common from Blackhawk are Green/Red and Blue (Arcane Beast and Arcane Stoic)
10-09 Epic from Pans Vale is Brown/Purple (2 x Arcane Skull)
10-16 Ultra-Rare from Drifting Sands is Yellow/Purple (Arcane Plains)
10-23 Epic from Dragons Claw is Blue/Purple (2 x Arcane Spirit)
Arcanes Required Calendar
06-19 Legendary from Divinion Fields is Brown/Yellow (16 Arcane Mountain)
07-07 Mythic from Broken Spire is Red/Yellow/Purple (21 Arcane Storm, 21 Arcane Dark)
07-14 New Kingdom Urskaya (1 Arcane Deep, 2 Arcane Lava, 2 Arcane Storm, 3 Arcane Spirit, 12 Arcane Venom, 12 Arcane Skull, 16 Arcane Mountain)
07-31 Legendary from Khaziel is Brown/Red (16 Arcane Lava)
08-04 Mythic from Mist of Scales is Blue/Green/Yellow (21 Arcane Swamp, 21 Arcane Blade)
09-01 Mythic from Forest of Thorns is Green/Brown/Purple (21 Arcane Forest, 21 Arcane Venom)
09-04 Legendary from Zaejin is Green/Yellow (16 Arcane Light)
09-15 New Kingdom Merlantis (1 Arcane Stoic, 2 Arcane Light, 2 Arcane Forest, 3 Arcane Blood, 3 Arcane Swamp, 12 Arcane Spirit, 16 Arcane Shield)
10-06 Mythic from Urskaya is Blue/Green/Brown (21 Arcane Shield, 21 Arcane Forest)
10-09 Legendary from Pans Vale is Red/Yellow (16 Arcane Storm)
??? New Kingdom Shentang (1 Arcane Stealth, 2 Arcane Blade, 2 Arcane Shield, 2 Arcane Plains, 3 Arcane Dark, 16 Arcane Lava, 16 Arcane Storm, 16 Arcane Beast)
There is also a new set of what appear to be 7 Guild Wars Troops - 2 Purple and one of each other colour, with no dates specified.
As always, all of this is subject to change at any time by the devs and updates/corrections are welcome.