Supposedly, the acquifer prevented them form meeting the [underground] parking requirements of the bigger 2 storey
enclosed mall.
From the renderings, the 2 storey spaces shown could be podium retail or even office space, so I'm not sure how the 2 storey
(and taller) spaces shown in the renderings fit into the overall project, but I don't think it'll be a full-on 2 storey mall corridor.
i.e. this space below appears to be formed by the edges of podiums:
http://dailyhive.com/vancouver/oakridge-centre-redevelopment-vancouver-2018-design
http://dailyhive.com/vancouver/oakridge-centre-redevelopment-vancouver-2018-design
The 2nd storey (podium) spaces on the left appear to be offices:
http://dailyhive.com/vancouver/oakridge-centre-redevelopment-vancouver-2018-design
http://dailyhive.com/vancouver/oakridge-centre-redevelopment-vancouver-2018-design
*********
WRT Hudson's Bay - unless QuadReal has come to terms with HBC, Ivanhoe Cambridge had (before the sale to QuadReal)
said that Hudson's Bay store would be staying in its existing location due to its current lease terms.