Doctor Who seems the most forgiving in that area. It has a built in etch-a-sketch mechanism between series/actors/writers and we've generally gotten accustomed to shrugging and go "sure, why not" again and again.

the Tolkien legendarium is a lot more loose than most people think. it's got a reputation for a high degree of specificity and detail, but that's more true for some things than others, and sometimes those details are contradictory between different versions of the same story throughout the editing process, with no clear indication of which one should be considered canonical

Doctor Who has gleefully gone the "everything is canon" route in recent years, especially applicable when your main cast constantly travel back and forth through time making significant changes to the course of events.

Well I'm currently in the middle of watching the new Scott Pilgrim series on Netflix and that seems to specifically be setup to flip everything canonical. Withholding final verdict until I finish it but so far I am liking it.

Warhammer CAN be that way sometimes (mostly 40k), though it varies heavily depending on who you're talking to. Some of that is due to retcons in the real world and some of it can be justified in-universe simply by the fact that their stage is the entire Milky Way galaxy, there's a LOT of wiggle room to be found there

Back in the day, Conan Doyle was sick of Sherlock Holmes.

In the first story, Watson had a shoulder injury from his time in Afghanistan, and in a latter tale it was a leg wound.

Loose interpretation is something lots of videogames use on purpose with an "unreliable narrator" POV

• dark souls, bloodborne, elden ring games are pretty much built on it. Most of the lore is given through item descriptions, so tying up the big picture is usually the result of interpretation
• Elder Scrolls games use the unreliable narrator trick a lot as well, the issue is that it's also used by writers to retcon stuff into more generic material. Since it's an open world action RPG with some level of choice they've made the weird decision to have all possible actions canon at the same time, even contradictory ones

The Elder Scrolls even has an alternative current that aims to destroy the concept of canonicity itself, it's called c0da and they're basically trying to turn fan fiction into having the same legitimacy as ingame canon. It's a bit weird but it's led by one of the original writers for the elder scrolls, who happens to be one of the main influences for Morrowind, the best Elder Scrolls game

I feel like super hero comic fans have a bad rep, but are more easy going about this than one may think. Things kind of drift in and out of continuity all the time. Especially if we’re talking about a big creator. Grant Morrison misremembers Batman’s son’s origin? Okay, that’s the new origin! He wants to bring back the second Robin’s red hair, which was written out twenty years ago? Okay, that’s a thing again.

Every Miku is canon.

Marvel? When in doubt, it’s another universe.

You're taking about "loose canon" but the whole conversation is already about Mel Brooks.

TTRPGs usually have a fairly loose canon, and Paizo definitely like to lean heavily into the multiple mythologies aspect.