people who have been in fandom for more than five years surely had a different fandom experience where many scenarios didn't exist yet.
Hm. There's nothing new under the sun. But, yes, as canon grew it opened up a variety of new scenarios and closed the door on others. Heh. I've been bemoaning the lack of pureblood!wealthy!Snape in fic for the past two weeks. ;D It wasn't my favorite cliche, but it used to be pretty common, so it was hard to see it completely disappear overnight.
for me canon and fanon is a muddled mess. i don't often clearly distinguish it and there are fanfics that i somehow regard as canon.
That happens to me, too. Especially if it's from books 6 or 7. I know I mix up a lot. And I am a huge fan of 'fanon facts'. Those kinds of things everyone just 'knows' but isn't canon. Like that Snape is taller than Harry (he likely isn't). Or that Harry's hair is lighter in color than Snape's (they both have black hair). But both of those things read as 'off' to me if people follow a more canon interpretation.
there will be more fics that deal with an aged harry and severus. i'd like to see that
*Nods* Me, too. But that is a very specialized niche, I think. Moreso even than chan. Consider the reaction to how old Draco looks in the epilogue of DH. People don't consider old as sexy. And it's not only the young people who think that way. The biggest outcry I heard from Draco came from women in their late 30's and 40's.