I would simply remove the Xindi from Enterprise. If they had focused on exploration and building the links between the Andorians, Vulcans and Tellarites there was enough potential there without a story arc that was essentially a middle finger to existing canon.
How was the Xindi arc a "middle finger to existing canon"?
I'm assuming he means that the Xindi were never seen, heard from, or talked about in TOS, TNG, or beyond. Which, based on their attack on Earth, does seem a bit far-fetched. But then again, we never saw Suliban, Denobulans, Kreetassans, etc. either, so take that how you will.
(Personally I don't think the Xindi were a "middle finger" to canon.)