Funny that this comes out now. A few days ago Australia Day was celebrated. Or, as the native Australians call it, Invasion Day. Fair assessment, all things considered.
That said, I find the idea of "white saviour" to be a little...eh, at least in the examples given. Usually within the confines of the setting, the character's ethnicity has no relevance to the story. This may have some bearing in Last Samurai or Dances with Wolves (neither of which I've seen), but for the other examples:
-Avatar: Well, let's get the "movie people love to hate" out of the way first. But to start off, this is a case where the character's ethnicity has nothing to do with the circumstances presented. But that aside, is it a saviour movie? Um...well...
To be honest, I've never seen Avatar as a "Indians in space" story, but rather an inverse on the idea of alien invasion. It's part of why I've never seen Avatar as being cliched. Because in many stories, it's a case of "aliens invade, humans win, aliens are badguys." Here, while the humans are 'invading,' they're being restrained about it, working for over 20 years before the shit really hits the fan, and trying to find a diplomatic solution. They fail, true, but I find Avatar to be both a cold movie, yet also a sympathetic one in its implications. The na'vi are 'better' than humanity, but it's a status that's rooted in their biology. They're taller (because their world's low gravity allows it), they're stronger (because their biology allows it), and they're more culturally and environentally stable because their psuhelu (sp.?) allows it. Humanity has produced its own wonders and innovations (getting to Pandora in the first place), but while some rise to meet the challenge, others don't, and taking the film to a possible conclusion, humanity is doomed by its failure, both on Earth, and on Pandora. And the universe doesn't care. Same way humans traditionally win against invading aliens, the na'vi win as well, by using their natural strengths with tactics Jake gives them. Because apart from Jake's M60 and Trudy's Samson, the na'vi are fighting with their own arsenal, and win because of numbers in the end. Jakes helps them, sure, but it remains their own triumph, and Eywa's in a sense. Make of that what you will.
-FernGully: Ah, FernGully. Been ages since I've seen it, but I've never seen it as a "saviour" movie either. Because, looking back...what does Zach actually do? As in, if we see the story as ultimately a conflict between the forest and Hexus, what does Zach do to affect that outcome? From what I remember he's the one that shuts down the machine powering Hexus, but it's ultimately Krysta that saves the day that imprisons him. FernGully is far more a green film than a saviour film, in that most of it is Zach and Krysta bonding, and Zach learning about the beauty of the natural world. Humans ultimately release Hexus, but they're never presented as an antagonistic force, but rather the catalyst for the story. I actually see FernGully as being more akin to Furlings (anyone remember that) - yeah, it's a human that causes the gas seepage, but it's the catalyst for the story, not an adversary within it.
-Stargate: Of the three examples I've listed here, this comes closest to saviour territory. Speaking personally, Stargate is a weird one for me. On one hand, I can admit that most of the love for Stargate comes from SG-1 (and spinoffs), and that while the movie sparked the franchise, it's generally regarded as being "meh" taken on its own terms. I kinda agree, but while I like SG-1, there always felt like there was a disconnect between the TV series and its source material. But that's a discussion for another time. But going by the film itself, there's the saviour element - white men from the USA help primitive peoples that happen to correspond to an Egyptian (Middle-east) culture, arm them with technology, and help them overthrow their cruel master. And the main protagonists are all white. So, maybe.
On the other hand, I don't personally see it as being analogous to any 'white saviour' concept. Within the movie's lore, it's Ra that jumpstarts human civilization, and if we factor the tv series into it, we can infer that most, if not all of humanity's major civilizations were given the basis for their architecture and culture by the goa'uld. Ra is both creator and destroyer, so to speak. That remains true on Earth, and becomes true on Abydos. Ra gave Man technology, Man used that technology to overthrow him, Ra seeks to destroy humanity through its own technology (the naquedah-enhanced nuke), but is destroyed by his own creation (beaming the bomb up to his ship). I've heard it said that Stargate is actually thematically based around the concept of science/rationality vs. religion/dogma, and that ultimately tech wins out over Ra on Abydos. If the movie has a theme, I'm more inclined to side with that interpretation, but I can get how one would categorize it as a "white saviour" film.