I suppose for the east coast people you can take the first flight out to California Monday morning and get back home in time to wake your kids up on Thursday.
The interesting part is the seems like a deal compared to cost of living of San Fransisco/Seattle and the salary slash of working in Phoenix/Las Vegas/Denver/Salt Lake/Boise.
$300-500 roundtrip flight every week, $250/night in a hotel X 4 nights, $50 Ubers to/from the airport at both ends, plus meals and other incidentals.
That's closer to $85k/year.
If you are staying in the city four nights a week you'll probably be better off getting a studio apartment, both in costs and comfort. SLU studios would be ~$2100/mo with utilities. If you assume $5000 for initial furnishing a studio will cost $30,000/yr instead of $50,000/yr for a hotel.
It'll also be faster to go between SEATAC and SLU on the Link Light Rail than an uber (unless you are traveling between 9pm-6am), which costs $2.25/ride compared to $50. So that reduces the costs by another $5000.
If you claim Washington state residency you can probably stop paying your current state income tax (Washington doesn't have one) which will save you thousands or tens of thousands a year.
After looking deeper into it my $15,000 estimate is way too low, but your $85,000 is much higher than reality for Seattle.
Doing 10 hours/week on a plane sounds hellish.
If they force you to any office, then their stated reasoning is BS and they just want to lord authority over you.
What about this seems inconsistent with Amazon's business practices?