They will probably add it later, they cant really do both in one day unless they start out at 3am or earlier since the park still open at 9am. A lot of people did the same day pick-up and they have a pretty generous pace requirement in comparison to others and i am not sure they even really enforce it either, you can probably stretch it to 20min/mile and they wont haul you away.
I have ran in a course that does both a 5k and 10k and that wouldnt work with the universal course since they do not simply lengthen the 5k to 10k, the 10k version snakes around more creatively and there would overlap and confusion if done at the same time. They simply do not have enough land and that is why a half marathon is likely impossible.
They might be able to do one after the other with the way they do corrals, they’d have to change their cones and change the course real quick and accurately and then go through the corrals again. Add in the kids 1k which probably take another hour or so from start to finish then the whole thing is going to take entirely too long.