The reason the timeline is ambiguous is because the movies after Mad Max are legends being told years later. Note the narrator of 2/3 isn't Max and his fate is left unknown. It's a convenient way of waving away continuity concerns, or questions like "why is the gyro guy in two different movies but he's two different characters I don't even what?" That's how they can set a sequel that's "somewhere between 1-3" without really caring much. Heck there's supposed to be like 10 years between 1-2 and another 20 between 2-3, there's tons of room for ambiguously placed sequels.
I mean, Fury Road should be before Road Warrior because he has the Pursuit Special with the modifications we saw in RW... but Miller can always play the "lol, unreliable narrator" card.
And we don't get Mad Max 4: Beyond Beyond Thunderdome because the marauders have mostly died off or become "civilized" in places like Bartertown.
Leave the poor guy alone, he's done.
Anyway, this trailer looked like liked more of the Indiana Jones slapstick from Thunderdome. Maybe it was the goofy music.