Look at the specs that I posted. They were from the Mobil Web site at the time (ca 2004/2005) and they showed the specs of D1 and M1 T&SUV clearly did not match. I'm also almost 100% sure Terry said these two oils were not identical.
In general, people use to confuse M1 T&SUV with M1 Turbo Diesel Truck, I personally think mori is right, the TSUV was never Delvac 1 rebadged, the turbo diesel highly likely could be.
I do remember when the specs were different for the two, then they seemed to merge, and then that FAQ statement showed up. Maybe it was all a temporary thing while they were planning the TDT and T&SUV split in marketing, who knows? Now you can't even find a N. American web page for Delvac 1 on the Mobil web site anymore. This used to be the page where the statement was made, but now it has that Mobil 1 chart and no mention of Delvac 1 on the page at all.