@friessssssssss to me, it really doesn't matter.
I've seen a tvd fanfiction where the author didn't only swap actors for 2 beloved characters, the new face claims were even of a whole different ethnicity. From white to black, and tbh, it fit the concept of the story so well. The author also gave the characters a different personality. nobody complained. Didn't even take me a minute to get used to the changes.
It's just fanfiction and fun, nothing to be taken seriously to the extent that people should complain about stories if there is one thing they don't like. Like, if it hurts someone's feelings to see their favorite actor replaced by another, then that's a them problem. You can't cater to everyones needs and make everyone happy.
If people complain, ignore it.