Sounds about right. Just had my 5th one, ordered October delivered end of Feb but that was one already in the factory build schedule. Factory orders were looking like 6 months at the time.
There is a severe shortage on the Bose systems, caused by the worldwide semi-conductor shortage. I believe that's why they bought out the "Newground" mode without the Bose. In fact, having just checked, the Bose is currently only listed as standard on GT Sport models.