So I decided to have some fun, and replaced several sounds with the Guildmaster's dialogue from Fable.
Specifically, the low health heartbeat (turning off the looping), the insufficient magicka sound, the sneak attack sound, the new quest sound, and the quest completed sound.

It's quite a fun change, and I can see people wanting to try it, just for the lols.
But it would get taken down if I uploaded it, wouldn't it?
Is there some way I can anyway? Some kind of fair use?

this would not constitute as fair use, and is simply a breach of bethesdas EULA, so you would not be able to upload it publicly unless you got explicit permission from Fable developers to use their assets in skyrim.

That's a shame.

although, in reality, who knows.

there was a macho man randy savage dragon mod released a long time ago that used blatant copyrighted material and everybody loved it without ever bringing up any issues.

You can just upload it and see what happens. the worst thing that could happen is the file gets deleted or you're asked to remove it.

Or you get banned from the site you upload it to. Worth the risk? Probably not. It's a violation.

Contact a staff member or administrator of whichever upload route you choose if you want to be safe.

Worst case scenario is that they say no. Or, if you don't ask and put it up, the file may be removed/deleted and you may be banned. And if that happens, it's not like it's hard to make a new account for whichever site (I'm assuming you're going to use the Nexus).

"The guildmaster was found murdered one day. They say he had the words 'your health is low, do you have any food?' carved into his forehead."