No, the bus must be rerouted to Main St when it leaves Vleigh Place (i.e. follow the old Q74): north on Vleigh Place, right at 73rd Terrace/75th Avenue, quick left into Main Street. Then you can turn right on 73rd Avenue and keep going.
Of course, the folks on that part of 73rd Avenue might also go NIMBY.
I would go further and say to give up the Q73 idea in favor of extending the Q64 along 73rd Avenue east of 164th Street. (Of course, I would also expect the folks on 73rd between 164th and 188 Streets to fully oppose a bus on their street.)