In general, I’d say you’re right that Alberta wouldn’t have a large population of francophones. But, especially in anglophone provinces, French speakers tend to live in French communities.

Like in my province, you could carve out ~80% of the land and have about 97% English speakers to 3% French speakers. But the remaining 20% is nearly 90% French speakers.

Packaging having both languages on it is a federal level legal requirement, since we are bilingual. However, the stop signs are more a regional thing. If there is a francophone population in the area, and you’re not in Quebec, you might see both on a sign. In my home province, we have the dual language signs wherever the French speaking population is large enough to warrant it, but everywhere else has English only.