I saw that also, but since it's sent from Denso (I assume) I believe they just list long shipping times whereas I would expect it to actually be sooner or as long as densoproducts. I understand your concern though. I don't have any association with them. Just sharing my assumptions which may be wrong.
I rebuilt mine for some reason, even though reman would have been about the same price. I did bearings, brushes, a couple washers, and the rectifier. Not the regulator since mine seemed fine and that's the most expensive part to buy separately. Gave everything a good clean and installed it a few days ago. I guess my reasoning is that I knew all the parts were new, whereas I've heard some reman units don't replace everything. No telling if that was a wise choice though. Time will tell.
Best of luck with the install.