From what I recall - the application was not rejected by the City. Ontario municipalities have a time limit in which to respond to such applications. If a city does not respond - for whatever reason including, in Toronto's case being short staffed due to lack of approvals (and by whom I wonder) to hire to fill vacant positions in the Planning Department - then the applicant has the right to appeal directly to the OMB for approval of the project, which is my understanding as to what happened in this case.
Regarding timeframes for an OMB appeal - well, it can vary depending on the adjudicator who heard the appeal. In the case of another Freed proposal, for the additional floors at 621 King Street West, it took in the order of nine months for the decision to be rendered.