Thanks, Laura!
I went over to GEDmatch, and happened to notice that "Beta" option, before coming back to read your advice. I think I'd checked it out before, some time ago, but hadn't gotten into the habit of using it.
So yes, I'm seeing those links now - over on the "Beta" option.
When I do that on my brother's, I don't see the Wiki option for me on our match.
I don't think I'm using an alias, and it was already on "disable". What you say above says that that should have been OK, but it was already there so maybe I'll try the last option, and see if that works over the next two days.