Drilling it like that gives me the creeps. Eventually (in 5, 50 or 500 years) the job will have to be done right, and all those holes will just make it harder.
Besides, I can't imagine they really are going to increase adhesion much over what is already provided by the pitting. It doesn't take much to key two surfaces together when they are bolted together flat like this. Also these fillers are not very strong in sheer so I doubt drilling down a full 1/8th really adds anything to the repair.
I could be wrong, though. It would be interested in trying it both ways on a dozen or so machines and see if there was any significant difference in how long the repair lasted.
Myself, I have a skived, tapered gasket that has been doing the job nicely for 30 years, but I think next time I have to to do the job I'll use whatever the latest and greatest high-temp filler is - but without the holes.