Random things that jumped out at me in the trailer: -
1) Fully half of the trailer's run time is taken up by archival footage from the first three seasons. Impossible to be sure, but I think what we're seeing may only be from three or four episodes of the first half. Either they don't have a lot of it in a finished state, or they want to keep the cards very close to the chest for this last season!
2)
@0:47 When the new footage does finally kick in we get a huge wolf, obviously inspired by Moro from 'Princess Mononoke', just like Filloni always wanted. The possible connection to Ahsoka is of course the most obvious, but it may just be a creature from Lothal as they're clearly seen in the old temple's wall art. Not that these are mutually exclusive possibilities.
3) Also in these same shots, it seems Sabine is either exhausted, or unconscious. Her body slumped, arms loose and head down, curiously with some kind of box balanced in front of her. Seems like they're escaping something, perhaps after obtaining said box?
4)
@0:51 We see the Ghost evading a pair of TIE Defenders. The planet looks reminiscent of Shantipole with the rock spires and low cloud cover, but the scenery and weather seems significantly different so probably a different planet. Given the presence of the Defenders it may just be a part of Lothal we've not seen before now.
5)
@0:56s Yavin 4. Massassi temples. 'Nuff said!
6)
@1:00 I'm assuming from the flat baked ground that this is Mandalore itself, possibly right outside Sundari.
7)
@1:01 Bo Katan Kryze kills a TIE and flies straight through the wreck as it's still exploding. Awesome.
8)
@1:02 U-Wing on the same cloudy rock spire setting as before, blowing up what looks a lot like the energy shield projector on Endor.
9)
@1:04 This is interesting. Not because of the RO tanks but because it looks like Hera is in a very different outfit. I'm guessing she's undercover? That would make sense if this is Lothal as you'd think her likeness (and the whole Ghost crew's) to be plastered on wanted posters all over Lothal, if not the entire outer rim territories by now.
10)
@1:05 Saw standing in front of what can only be one of those huge kyber crystals. Presumably still on the trail that'll eventually lead him to Jedah.
11)
@1:06 That has to be Sundari, though under Imperial rule it's outer shell is looking decidedly Death Stary, with a sickly, almost eerie green light from below. For some reason it's reminding me of Minas Morgul.
12)
@1:08 Bo Katan looks weird translated into the Rebels aesthetic. But then I thought that about Vader, Yoda & Ahsoka too and quickly got used to it.
13)
@1:09 Ruhk is looking more alien and yet at the same time less bestial than I recall the Noghri looking in the EU. I think it's an improvement.
14)
@1:14 More of Hera and Zeb apparently in disguise.
15)
@1:15 Clearly some kind of U-Wing variant. Possibly the more common civilian model mentioned in the RO ultimate guide?
16)
@1:21 Captain Kallus? I'm assuming this implies Hera got her promotion to General by this point, otherwise that'd be weird.
17)
@1:27 Kyber shipment goes boom?
18)
@1:28 Is this a new world, or has the Imperial exploitation of Lothal over the last few years really screwed up the atmosphere?
19)
@1:31 Yet another shot of Hera & Zeb in their apparently ineffectual disguises.
20)
@1:35 Hey kids! X-Wings! *applause*
21)
@1:36 Red Leader standing by?
22)
@1:37 Mandalore the Ginger!
Crazy theory, what if Ahsoka is the Wolf in the trailer? Crazy force magic.
Are you nuts? For that to even be possible Ahsoka would have to have been infused with the lifeforce of a powerful force being capable of transforming into a giant creature at will!
Also look at the wall paintings behind Kanan when hes facing the wolf. One of them looks like Yoda, even has a lightsaber on his hip.
Yeah, I can see it. Probably just a little easter egg, but still interesting. Also note, he's not the only figure there with a sabre on his belt. Interesting and possibly significant that neither are drawn or activated. It's not often Jedi are depicted like that.