As reported on by the amazing Oshan the deal for Arriola is now done and he's already reported to the team. Looks like the MLS isn't blocking the deal anymore. And it's another trade with a 1st-round draft pick and $300k in conditional GAM. Though they aren't any contract details known at the moment as the MLS still has some hang-ups over the deal. But since he's coming in he's someone who should add to the team ASAP.
Paul Arriola trade has been completed, officially a Sounder
It's done and dusted.