I didn't realize ranked choice had become a partisan thing. I suppose right now there's a certain visibility with the divisions between center-left and far-left in the Democratic party, which may have cost them the 2016 election, but it seems to be that similar divisions could be calculated to have cost the Republicans 2020.
I'm not the biggest fan of alternative voting systems, in that I don't think they'll make people as happy as they hope. I don't believe it will upset the basic two party system, since people won't generally agree on a specific third party and will all end up with their second choice (which will end up being one of the two major parties).
Still, I don't think it harms anything. The worst that could happen is confused voters, but that happens anyway. And I suspect people will see the lack of big changes as proof that it was rigged all along rather than a consequence of any electoral system with a single winner. Which, again, is just where we are today. And who knows, maybe it will actually make people happier to think that their voices were heard, even if it didn't radically alter the outcome.
So I don't see how it's in the WSJ editorial board's interest to make it a partisan issue. Perhaps it's just the generic problem of "If they want it, it must be bad"?