Perfect example of the TOC process would be the central London Crossrail stations - stations built to support the weight of development above, and station systems (ventilation, fire safety etc) are separate from any future building on top. As with the TOC process, placeholder designs for the OSD (over station development) were used until actual planning permission was obtained and agreement reached with the developer.Infrastructure Ontario has published architectural plans for the TOC sites, and the subway station layout is very similar to what is shown in the rendering in terms of being an open space, with elevators located between the sets of escalators/stairs, and columns around the perimeter. So while the rendering lacks the tower above the station, it seems the layout shown in the rendering is designed to support an overhead tower with no major changes.
Here's the Tottenham Court Road Dean Street entrance for example in 2019 and 2021 - station "pavilion" basically complete, and now having a building being built on top of it by developer Galliard Homes. Looks like they paid £43m for the privilege.