Wasn't the Manulife underground connection t/w the subway of a later date (80s/90s)?
Just as a point of referrence here are the stations with or within proximity to underground concourse connections to shopping/residential buildings:
Islington (Clarica Centre)
Dundas West (Crossways Mall/Bloor GO Stn
future)
Lansdowne (1380 Bloor W
proposed)
Dufferin (Dufferin Mall
proposed)
St George (U of T)
Bay (Manulife/Cumberland Terrance/80 Bloor W)
Bloor-Yonge (1 Bloor E/HBC Centre)
Sherbourne (Rosedale Medical Centre)
Victoria Park (Teedsdale/Dentonia apts)
Scarborugh Centre (STC/Civic Centre/Bell Comm)
Yorkdale (Yorkdale Mall)
Lawrence West (Lawrence Square
future)
St Clair West (St Michael's College/Loblaws)
Dupont (Geogre Brown College
future)
Museum (ROM/Hart House
future)
Queens Park (700 University/Ontario parlimentary buildings)
St Patrick (AGO/OCAD/other buildings)
Osgoode (Four Seasons/Opera House)
St Andrew/Union/King/Queen (fully integrated in PATH network)
Dundas (Atrium/TCT/Eaton Ctr/Metropolis/Olympics/Ryerson)
College (College Park/700 Bay)
St Clair (St Clair Centre)
Davisville (Davisville Centre)
Eglinton (Orchard Pk Apts, Yonge-Eglinon Ctr/Canada Square)
York Mills (York Mills Ctr)
Sheppard (Sheppard Centre/Procter Gamble/Nestle Building/55 Sheppard W/Madison Ctr)
North York Centre (NYCC/Empress Walk/civic centre/Novotel)
Finch (5750 Yonge/ North American Life/ Place Nouveau/condominiums on Pemberton Avenue)
Bayview (500 Sheppard E/Bayview Mews
future/YMCA)
Bessarion (future condos)
Leslie (North York General/IKEA/office buildings on Old Leslie)
Don Mills (Fairview)