Do you have a source for this? So far as I understand, all comments about UA removing club access for pax to Canada are purely speculation, and I don't recall even seeing a post with a report of any staff member has confirming this. The only thing I've seen is somebody speculating without evidence that a change for premium cabin to Canada being re-named to 'First' from 'Business' is driven by a change to Club access policy. Seems indeed to be speculation and nothing else, and that folks are still being admitted. Maybe it will happen, but no real evidence saying so. Let's not forget that prior to the merger, UA called front cabin to Canada F, and still allowed Club access. Furthermore, I don't think AA or US (and maybe CO before) allowed it, and that never initiated change at UA.
In the alliance, they are the same.

And even given that, any UA premium cabin passenger (or UA Gold/higher in economy) does get club access on all international trips currently, including to nearby countries such as Canada, Mexico, Caribbean. Even SJU gets access, and that's not even technically international. Again, a supposed change to policy with respect to Canada is speculation, and until any change, all international premium cabin pax still get access.