Seattle here, and a real estate nerd. This is almost entirely an artifact of the financial instruments used to pay for these buildings, regardless of any Seattle policy changes. The Seattle Times has always been a conservative rag, and their editorial board hates the new mayor, so they hit the "Seattle is dying" story as often as possible. They've got a long history of this whenever there's leadership they don't like…
You can always pay less on your mortgage or any other debts if you are in a crisis and negotiate with the lenders. They prefer this immensely over not receiving anything at all. And in the long run they also receive more interest this way.
It's very common especially for businesses to enter these kind of negotiations with the banks, and not very uncommon for individuals either.
So it makes much better sense for everybody involved to sublet these spaces for market value, even if that income doesn't cover the original mortgage, because something is better than nothing. Somewhere there's a giant perverse incentive in situations like this.