I think the problem here is that it's a box to type your pokemon into first, and a search/filter system second. The search/filter system is only there to help you type a pokemon in.
If the "Ice" search was part of the box, like if it said "Ice, wish" I can understand wanting it to exclude Wishiwashi. But it's autocompleting "wish" and it's a box to type pokemon into.
With a drastic redesign of the teambuilder it would be worth doing it that way, but as it is now, this is a really minor convenience issue not worth upending the purpose of the box as for typing pokemon into. I'm going to have to reject this.