The reverse has happened as well:
United Devalues Partner Earning Structure
http://thepointsguy.com/2015/01/unit...ing-structure/
When it comes to earning on Air Canada, be on the lookout for discounted Economy fares, as they will only earn 25% mileage accrual for flights within Canada.
https://www.united.com/CMS/en-US/mar...spx?ItemId=313