but the only way it doesn't make a difference is if you don't read anything that's AU.
That's your opinion, sure.
I read a metric fuckton of AU, and IMO it really doesn't matter whether your College AU is set in 1990 or 2018. Either way, it requires the exact same acceptance that, "Yo, this is not meant to be canon compliant."
Now if you want to add in, say, Vampires, then that requires an addition level of acceptance that, "Hey, so there's shit in this universe that doesn't exist in the real world." Or, if you want to set your fic in the 19th century, then sure, that adds in the additional level of acceptance that "this fic is going to be set in the past and things are gonna get historical up in here."
Re: DA
That's your opinion, sure.
I read a metric fuckton of AU, and IMO it really doesn't matter whether your College AU is set in 1990 or 2018. Either way, it requires the exact same acceptance that, "Yo, this is not meant to be canon compliant."
Now if you want to add in, say, Vampires, then that requires an addition level of acceptance that, "Hey, so there's shit in this universe that doesn't exist in the real world." Or, if you want to set your fic in the 19th century, then sure, that adds in the additional level of acceptance that "this fic is going to be set in the past and things are gonna get historical up in here."