I have booked a USA-YYZ-Europe AP saver award in business (I) where the initial USA-YYZ was a single cabin CRJ-200. Just got an alert that the aircraft has been up-gauged to a CRJ-900 now with a business-class cabin. Are we eligible for an upgrade to the business class cabin without paying additional miles? If it matters, the USA-YYZ economy is booked into (Y)-class.