The site plan approval for the site allows for two mid-rise buildings. It was discussed in this thread earlier that the developer put the land up for sale, though it was advertised as "shovel ready" meaning the purchaser would presumably be building buildings in substantially the same form as set out in the site plan approval. It's unknown (to me at least) if the land sold, so it seems possible the developer could still go ahead if the offers (if any) for the land didn't mean a sale makes sense.
For what it's worth, even if a new developer came in and bought the land and sought to get a new site plan approval, I doubt another high-rise would be approved for the site. First, that seems like it'd be a lot of density for the site. Second, I believe the tower here was approved back in the early-mid 2000s, and based on what is being approved in the equivalent lands down Queens Quay East (see the heights of the Waterfront Innovation Centre, the Arbour, and the T3 Bayside buildings) it doesn't seem like the current planning rationale would allow for the approval of a tower that close to the water.