I think you’re spot on. One of the reasons I leased a leaf when I did is because when you do, Nissan recognizes the rebate immediately, and the price reflects that. At the time, the lease rate was effectively zero, and the post-lease sale price was higher than it should have been - so the delta between the price and the buyout was so small that the payments were ridiculously low. The best part was - they assumed the resale would be MUCH higher than it was, so they took a bath on the thing. I could have bought it for almost nothing at the end of the lease... but that’s another story for another day.
Your mileage may vary - pun intended - but yah... all tax breaks come in April of the following year... and you better hope you’ve got a tax bill of more than $7500 or you may see nothing of it.