The WA-08 equivalent looks like it might be a little more D than in OTL. Pity Seattle can't have a CD all to itself.
WA-08 seems to be about two or three more points D than OTL. As for Seattle forming a CD to itself, imo it would probably be able to achieve that either in 2030 if the city continues to grow faster in population than the state average, or in 2030 or 2040 if the state gains an additional district.
Part of the issue with WA is it's relatively easy to get 7 "safe/likely" D seats on a neutrally drawn config, but it's also pretty easy to give Rs 5 seats they can realistically win.
WA is also generally annoying because there's no ideal place to cross the cascades, but for now 8 is the best option. The extreme urban-rural divide can also lead to troubles.
What I like about your map is it makes a true Seattle based CD without weakening 9 as a minority opportunity seat.
Also I was playing around on DRA and rotating 4 and 5 so they're east-west doesn't work out as nicely as I thought, so I think for now keeping them as is (as in your map), is the better option.