New leaks of variant Riptides and some variant Battlesuits just hit the internet.
I can almost guarantee you that the huge gun is Strength D... Death of Wraithknights brought to you by Tau.
So I think the second picture is a new stealth riptide or possibly a new Commander in a now extra large suit... Because if 40 is doing anything lately it is bigger is better.
Additionally, I think it is possible the Fire Warriors are a new sculpt, however it could just be the paintjob messing me up. Not entirely sure. BUt my Tau friend is insisting they are new, so lets go with that!