This Retail Insider article refers to the earlier La Presse article that indicated that the Bay in Montreal had been for sale, but provides more information about plans for potential redevelopment:
"A recent proposal to the City of Montreal to modify the historic 655,000-square-foot downtown Hudson’s Bay flagship store could result in the building of a massive office tower along with a reduction in the footprint of the retail space within in the building. What would result is a real estate asset that would feature substantially more office space than retail space.
The proposal seeks permission to demolish the unattractive circa 1964 back-end of the Bay building facing onto Blv. Maisonneuve (intended at one time to become a 200,000-square-foot Saks Fifth Avenue) and replace it with a 400-foot-tall office tower with 25 floors. The total office space, including levels five to eight of the retail store as well as the new tower, would span 678,000 square feet. The retail space in the building would be downsized to five levels (basement up to level four) spanning about 295,000 square feet.
The Sainte-Catherine Street side of the Bay building, referred to as ‘Colonial House’, is proposed to be restored as well as to see the addition of a public terrace overlooking Philips Square. The new grey glass and aluminum-clad office tower would feature a staggered design at floors nine, 14, and 20. A green roof is proposed as well."
https://www.retail-insider.com/retail-insider/2020/10/hudsons-bay-company-announces-division-to-redevelop-real-estate-assets