No. The right-angle adapter is required for the DOS card to work because has custom chips that pretend to be an '040 CPU. 100% of the data that comes into or out of the 601 PDS and the DOS Card is translated by the adapter.
The same thing happens on the LC PowerMac systems. They have a '040 PDS slot but if you look closely at the logic board you will see that the circuit traces from the "PDS" (it's not "processor direct" at all) slot all go to a chip on the board that fakes '040 signals … just like the right angle adapter here.
CPU upgrades won't work on those slots either.