Thanks for sharing. It seems the Amazon US pre-order is up now. Just to be sure, this cover is by Casey Coller, right?
Nick Roche Transformers Lost Light Issue 20 Nick Roche Cover Art - Transformers News - TFW2005 It does look like they've just reused the issue 20 cover for that image though so it may well be a placeholder.
It's gonna be a thick one not only because it contains 7 issues but also because Roberts said the last one (#25) will be oversized.
Optimus Prime vol. 5 is also up for pre-order (not sure if someone reported it): https://www.amazon.com/Transformers...ks&ie=UTF8&qid=1528310625&sr=1-3&keywords=idw Trapped between Shockwave's attack and Unicron's onslaught, Optimus and the Autobots struggle to make sense of what's left of their world, as Optimus' colonist soldiers contend with a brutal reality--they have no homes to return to. Plus, Shockwave reveals ancient truths--as an old friend tries to reconnect with Cybertron. Collects the 2018 Annual and issues #22-25, which conclude the series.