Thanks to fellow Seibertronian Autobot N, we now have what will probably be the entirety of Transformers Siege Wave 1 revealed. The listings for the remaining Micromasters, Battle Masters, deluxe, voyager and leader all come from Midtown Comics. These listings were accompanied by the listings of the wave 1 toys we already knew such as Optimus Prime and Hound. These listings reveal the identity of the mysterious Deluxe "S", which turns out to by Skytread, which was the name they used for Flywheels. Now this can mean many things. It can be a deluxe that can have 2 alt modes, or a splitting partsformer, similar to Cog, with elements of the two alt modes, or even two legends class toys, though that last one might be a stretch for the deluxe price point.
Here are the new listings:
BlowpipeSkytread!ShockwaveAirstrike PatrolMegatronThis means the full wave 1 for Transformers Siege is the following:
Micromasters: Race Patrol, Battle Patrol, Air Strike Patrol
Battle Masters: Firedrive (Firebolt), Lionizer, Blowpipe
Deluxe: Cog, Hound, Sideswipe, Skytread
Voyager: Optimus Prime, Megatron
Leader: Ultra Magnus, Shockwave
As you can see, Shockwave is in the leader class though with both him and Magnus being in the Prime Wars contest for a leader class toy and with us knowing that all those toys were going to have an evolution gimmick (with Seige Magnus still sporting that), it could be that leader Shockwave would be a voyager Shockwave with armour pieces for an ultimate form.