Would you consider a Wikipedia brain implant to be a transhumanist modification?

That's a weird way of putting it. Would I consider an implant which consists of a large chunk of memory with some processing and an efficient neural interface to be transhumanist? Yes, of course. It will give a lot of useful abilities and just filling it with Wikipedia looks like a waste of potential.

I don't think trivializing transhumanism to minor cosmetics is a useful approach. Artificial nails make better screwdrivers than natural nails, so is that also a transhumanist modification?