I think one of the problems with the way we talk about media in fandom is that we often say “canon” when we really mean “the text”. What is and is not canon is at least partly a question of authority and merit, and will inevitably be litigated as such, but you’re going to arrive at some very strange conclusions if you try to use the same tools to litigate what is and is not present in the text.
Sometimes you’ve gotta take a step back from questions of canonicity as such and ask more fundamental questions like “okay, that’s a fascinating interpretation, but what actual words that physically appear on the page* do we have to support it?”
* or whatever the equivalent for the media at hand is
I’ve always felt that pretty much anything we accept as “canon” can be rejected if we take a somewhat unconventional interpretation of what is in the text (or on the screen, etc)
Which can range from totally plausible but surprisingly rare interpretations, like: “when this character explicitly said this thing, they were not 100% correct and/or honest”
…to technically possible but far-fetched interpretations like “ok this part was all just a dream/hallucination”
….Anyway, I love Tron fandom because you don’t even have to do very much of any of that
so much of what we see onscreen is left VERY much up to interpretation. and yeah there are common interpretations that get treated as “canon,” but you can so easily take a different one and have it make perfect sense in the wider context.
Did Ram die? We see his visual appearance disintegrate but what does that mean for a program? Is that like his user interface, or his icon on the desktop? Flynn clearly thinks he’s dead but how would he know?
Is kissing a thing that didn’t exist for programs before Flynn introduced it? We don’t see anyone kiss before that, even though Tron and Yori appear to be romantically involved, and Tron seems surprised when Yori kisses him at the end. But there are all sorts of reasons that could be. (Not even beginning to get into what was normal for other programs. Who are probably much more diverse, in both physical abilities and behavior, than humans, because they’re literally created for different purposes)
Did Alan and Lora, and any of Flynn’s other friends, ever find out about the computer world, between 1982 and Legacy? We don’t see Legacy Alan saying he knew about any of that… but he sure acts like he knows a bit more than he’s telling Sam. I have a fanfic that’s pretty canon-compliant with the movies and actually explains a few more onscreen details than the standard interpretation does.
Did Kevin Flynn die at the end of Legacy? He “reintegrates” with Clu, and Quorra had previously said he wouldn’t survive doing that. But how would she, or Flynn, or anyone know? It had never happened before.
There’s not even any real clarity on how the laws of nature in the world work. And there are multiple different worlds, which could easily have different laws, and/or upgrade them over time!
And, as for which works to accept as canon– I’ve been talking mostly about the movies, but there’s also comics and video games and novelizations, and many of them directly contradict other parts of canon (sometimes in downright unreconcileable ways, like the storyline of Tron 2.0)…
So, on top of all the interpretation questions, I feel like there’s also a significant basis for canon AUs. That is, I think it’s reasonable to imagine the Digitizing Laser messes with the fabric of reality, enough to create splits in the timeline, where each time someone uses it they come out in a few different branching universes afterwards.