I'm glad that we agree on the definition of "Canon-Divergent AU."
Since I can't edit my comment to make my position clearer, here it is in detail. Somewhat excruciating detail, to be honest!
I agree with everything said: in sum, "Canon Divergence AU" is too vague to be helpful.
Currently we have two categories of AU-ness in terms of setting—Modern/Mundane and Genre (the latter possibly being split into two, even clearer)—and I welcome the chance to opt-out of these things.
Now that the mod has handily clarified the "Canon-Style Plot" tag, there is no catch-all option for, as you say, "retain[ing] the canon setting" whether or not the story "veers off ... in terms of plot development."
The only option that suggests anything at all about keeping the canon setting is "Worldbuilding." If everyone who wants a canon setting ticks this box, what happens to the people who really do want to focus on the construction or aspects of the setting?
As you point out, "Canon Divergent AU" doesn't indicate anything about what sort of plot change is requested. Without a letter, is the safest possible option to assume it means Fix-It fic, or to keep the canon tone?
What about someone who just wants a canon setting, and doesn't care about whether there is a divergence or not? Do they opt into or out of this tag?
If all I got was a placeholder letter and my recipient's tag choices, what tags are useful? "Fix-It fic" gives a sense of tone, and valuable character direction. It carries strong implications about what the recipient would be comfortable reading. "Canon Divergent AU" assuages precious little of the writer's uncertainty.
TL;DR: The popular vote for "Fix-It fic" makes sense, so does "Canon Setting with a Twist/Trope", just please don't leave us with the uncertainty of "Canon Divergent AU."
no subject
Since I can't edit my comment to make my position clearer, here it is in detail. Somewhat excruciating detail, to be honest!
If all I got was a placeholder letter and my recipient's tag choices, what tags are useful? "Fix-It fic" gives a sense of tone, and valuable character direction. It carries strong implications about what the recipient would be comfortable reading. "Canon Divergent AU" assuages precious little of the writer's uncertainty.
TL;DR: The popular vote for "Fix-It fic" makes sense, so does "Canon Setting with a Twist/Trope", just please don't leave us with the uncertainty of "Canon Divergent AU."