Just starting to lock in on our holiday itinerary (we’re there in Aug) and I noticed that according the the website there are NO EPA slots currently listed for Universal Studios (only for IOA). Is this normal?
I was assuming we’d get the chance to do EPA for both parks during our 3-day stay, now that looks unlikely… 
I’ve seen it at both parks in those months, but it’s not unusual for it just to be at IOA either.
Yes it is normal to not have EPA at USF in August. (It didn’t last year even with higher crowds than this year).
But rope dropping Diagon Alley in USF is still great since there is hardly anyone there. I recommend 1 of your 3 days doing that.