I'm not sure I buy the sharpness argument, as these coatings are literally a few molecules thick.
That said, I agree that sharpness and surface smoothness is key to successful soft aluminum cutting, as I commented previously. The primary reason I like the coated cutters is not for higher speed or production longevity, since I can't cut at what would be considered 'high speed' by today's standards and I do prototypes and not production as a rule.
For those of us who don't have or want a flood system, certain coatings offer a measure of 'anti pick-up' to the tool. So aluminum behaves more like an egg in a 'teflon' coated pan rather than a steak on the grill, often allowing dry machining with only compressed air for cooling and chip evac. Uncoated cutters always need lube of one kind or other, in my experience. For those with flood cooling, the debate is somewhat academic. Many moons ago I had a bridgeport with flood cooling and you really didn't even have conversations about material 'welding' itself to the cutters . . . on the other hand, I wan't cutting any soft aluminum back then.
The caveat with uncoated cutters on aluminum is that you *might* get away with a dry cut . . . . and you might not. The trouble is the way you find out that you didn't . . . which can get expensive in a hurry. I may as well add once again that in my view, mist 'coolants' like Kool Mist that I have tried are no better than dry cutting for soft grades of aluminum, however, something that I find very effective for band saw blades is 'grinder's paste'. This stuff is pretty miraculous at keeping aluminum from sticking to saw blades and grinding belts . . . . . just don't use it for final finishing if you plan to paint the part afterward.