the dealer could accurately track it with BMW on their computer from order entry to build to delivery--what's up with Yamaha?
<snark>You mean if one manufacturer has a perfect system for delivery date notification then all the others have too also? Hmm. Then shouldn't BMW's final drives be as robust as Yamaha's? </snark>
My larger point is that you're probably not going to get a definitive answer to your question and I gave the link to highlight some of the systemic reasons why Yamaha's a bit different.
This subject of delivery seems to come up about this time every year on the forum where a few people get antsy to get their bikes, wonder why Yamaha can't tell them for sure, and start freaking out.
And for the ones that start pacing out on the ledge and want take other with them...some of the old timers start poking them and reminding that in the old days you'd drop $500 on a PDP program where you gladly endured a 6 month window with not even a month identified...and glad to do it!
In the meantime, I'd stick to the notion that Yamaha announced that March was the month for '16 deliveries--and there's still 21 days left in it.