Correct, they are working in a sequence only, it means June 9th applicants are in the pool right now.
They also used to work at a 30% capacity, and they were hiring 62 new employees back in March.
So who knows, they are hired right now! And are working at full capacity. I've never seen so many people getting their AOR1 so quick!
If you are still worried, please look up common mistakes for Spousal Sponsorship and try to find out if you haven't missed anything.
Blank forms / no N/A on forms, incorrect information, missing / post and stale dated signatures and outdated forms are a few examples.