Here's my take, given that there have been four stages of Maul, those being with:
#1 - normal/flesh legs, as he originally appeared in Ep. I
#2 - spider-like cybernetic legs, as he first appeared in TCW
#3 - mechanical (chicken) legs made by Talzin from destroyed bodies of super battle droids, later in TCW
#4 - humanoid (slimmer) legs put by medical droids, also from TCW
So based on those, another PF from Ep. I may make sense because his horns and the double-bladed lightsaber from the film match the teaser photo. But IMO chances are slim for having this one, simply because we already have one in PF form. And to me that's one of Sideshow's best PF's made. His body overall is proportional, and the pose is very dynamic, and familiar. Unlike the 1:2 Legacy scale, which to me he seems to have short legs, and his pose seems very awkward.
Spider-like Legged Maul, #2, would be a great new/fresh statue; however, I think that will be a super massive PF -- especially if Sideshow makes it with those new elevated base styles! Though, if they managed to produce the Scout Trooper on a Bike PF, then anything's possible. But, as others have pointed out, the horns in the teaser photo are trimmed and civil, as opposed to how they were when he had the spider-like legs. And like others have pointed out, he didn't have his double-bladed lightsaber at the time.
As for the Maul with mechanical (chicken) legs, #3, Sideshow already made one, and I don't know how they can top that one. Also, at the time he had non-trimmed long horns and didn't have the double-bladed lightsaber, as shown in the teaser photo. So that's not an option either.
Then we have #4, Maul with his humanoid (slimmer) mechanical legs. Now, during that stage, his horns were trimmed/shortened, but he still didn't have his original double-bladed lightsaber. So my guess is that, this is the Maul with with his humanoid (slimmer) legs after he was defeated by Darth Sidious, and it's during the time when he's transitioning from TCW into the rumored appearance in the Rebels, where he replaces his lightsaber with similar to the one he originally had in Ep. I. To me this makes sense, because one other possibility will be to have on pre-Ep. I, but we already had Mythos that covered that timeline (and we know how that ended up.) So I'm betting on seeing this Maul to be revealed soon.
Which one are you betting on to see that it's revealed?
Makes most sense if its with his humanoid mechanical legs. Since they can basically only do new canon versions of characters. So this has to be something from either TCW or the Son of Dathomir comic. But he never had his doubled bladed saber in either of those...so I'm not sure exactly where this version of Maul comes from. I'd love for him to have his Dark Saber though. Would be such a cool light up feature for a statue!