“Business Class” fare but only economy + premium economy in the segments?

That’s usually a mixed cabin pricing quirk.

Air Canada (and most airlines) will label the whole itinerary as “Business” if at least one long haul segment is in business class, even if a short leg is in economy or premium economy.

But if your itinerary literally has zero business class segments and it’s still pricing as business, that’s weird. Sometimes it happens when:

The original search was filtered for business

There’s a phantom business fare bucket attached to one segment

The system is pricing off a higher cabin fare basis even though seats shown are lower

Airline pricing engines are messy behind the scenes. The label you see doesn’t always match what’s actually included.

If you’re not actually seated in business on any segment, I’d double check the fare rules and cabin codes before booking.