In like 99 percent of WBWL fics Harry ends up in Slytherin (or rarely Ravenclaw) and his brother ends up in Gryffindor.

But what if it went the other way around, with Harry going to Gryffindor and his brother going into slytherin.

If this was a bashing fic (and lets be honest 99 percent of WBWL fics are) then Ron would probably shout about Harry’s brother being a slimy snake, Dumbledore would engage in damage control and probably try to claim that he was sent to Slytherin to keep an eye on the Slytherin students and protect the school and someone somewhere would accuse Harry of having sabotaged the sorting hat.

But if it wasn’t a bashing fic what would the reaction be. Of course people would be shocked about a potter in slytherin and probably even more shocked that the brothers are in different houses (in canon a lot though not all siblings are in the same house) Snape would be angry and Dumbledore might think it curious though not game changing.