Strangely, to follow up, D'Alessandro/Waddell are now listed for JGP Canada too, even though they were also just listed for the just-announced JGP Slovenia. Since Canada is closer, I guess they're being shifted forward?
At present, the ice dance listings are:
Slovakia - Fabbri/Ayer (1), Bashynska/Beaumont (1)
Austria - Lajoie/Lagha (1), D'Alessandro/Waddell (1)
Lithuania - Galiyanova/Lochhead (1), Stairs/Graham (1)
Canada - Lajoie/Lagha (2), D'Alessandro/Waddell (2), Makita/Gunara (1)
Czech Republic - Bronsard/Bouaraguia (1), McIsaac/Circelli (1)
Slovenia - D'Alessandro/Waddell (3?), Fisher/Malette-Paquette (1)
Ice Dance's placeholder theory would seem to apply to the impossible third placement in Slovenia, so if so there are three slots left to be allotted, between the Slovene one and the two in Armenia.
I don't know how bad Corey's injury is, but once it was clear he could not do Canada, I can see why they moved Nat and Bruce to that spot. It isn't clear if Corey is out both in singles and ice dance for the rest of the JGP, or if he and Olivia might make it to at least one later event.