Unless there are some serious issues with SLS it will launch first.
Significant delays would be really, really bad for SLS. They already extended the lifetime for the SRBs...
I remember being called a idiot SpaceX fanboy that understands nothing about engineering when I said Falcon Heavy would launch first. And by somebody who worked at NASA as far as I can tell.
Unless there is a longer delay with upper stage refuel, they likely make it first.
> "Let's be very honest again," Bolden said in a 2014 interview. "We don't have a commercially available heavy lift vehicle. Falcon 9 Heavy may someday come about. It's on the drawing board right now. SLS is real.
Falcon Heavy launched four years after he said that. SLS still hasn't.
If you can't land it, it makes sense to sandwich the 'orbital altitude' and 'smile and wave around the moon' mission into one.
For SpaceX, focusing on the altitude seems to make the most sense. Especially considering that refilling may even be a higher priority than a moon pass.
NASA appears focused on inspirational discovery/science, while SpaceX is focused on making life multiplanetary. These are closely related, but fundamentally different missions.
They should've just done the full Wet Dress Rehearsal.