They might actually be able to get away with asking people to transfer at street level. It is a major inconvenience, sure, but the ride to there will be much more comfortable than the bus (as well as the potholed roads)
From The Star article linked above:
Otherwise, if the station is completely closed, then it would have a cumbersome bus transfer that nobody will find acceptable compared to a single bus to Yonge.
It might not be easy to terminate the route at Cedarvale because the crossover apparently is after the station. I doubt that they will phase the line in segments if all segments are ready except the stations. Trains can bypass the incomplete stations and the city will have to continue running busses on the route until construction is complete.
For the crossovers I found this on the crosstown
page:
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