I believe that would require the federal government to amend the constitution which is no simple feat. All premiers would have to agree to the changes which opens a whole can of worms since Quebec never formally signed on the original constitution, and the other premiers would very likely demand other changes be made as well to suit their own political agenda.
Then the provinces would need to have their own legislative amendments made to recognize the changes in both the constitution, which would also take time to pass as well.
If there is a change in government on either the federal or provincial level, and the party has a vested interest to undo those changes, all that progress gets flushed down the drain.
They’ve already been considering ending daily mail delivery, but they require a legislative amendment by the federal government to allow them to make any of the changes needed to keep their operations afloat. Here’s an article from earlier this year
I doubt it’ll be allowed anytime soon with an election on the horizon, but any sitting government that introduces the changes will be receiving a lot of backlash from opposition and rural residents.
The previous government allowed for community mailboxes to be setup to replace door-to-door delivery to make deliveries more efficient, and that got repealed because the poor elderly folks and people in the middle of nowhere would have to get some exercise to collect their mail. We all know what happened after the liberals got voted in, so I doubt much will change besides Canada post requiring subsidies in order to be able to operate by the very legislation that’s making them lose money.