Theater history question- Little Night Music

Got a theatre question that maybe someone knows the answer too- did some google searches but came up empty.

Little Night Music start at the Shubert Theater in Feb, 1973, but moved to the Majestic in September that year. Sunshine Boys then played at the Shubert, but actually moved from the Broadhurst to the Shubert- does anyone know why Little Night Music was moved down the street?

ALNM got incredible reviews and became a fast sellout, and I seem to recall that the producers mistakenly believed they could take advantage of the larger theatre. They didn't realize that the show was too sophisticated -- for want of a better word -- to attract an ongoing large audience. Partially due to the move, the show only ran 600 performances. The Majestic was a terrible theatre for the show...heck, the Shubert was too big for it. If it premiered today, it would probably have opened at one of the 1,000 - 1,100 seat theatres, and probably run longer than it did.