I lived for 15 months in the Tacoma region in the early 80’s, and noted even then...long before housing prices escalated...that there just wasn’t much of a black population in the Tacoma-Seattle region.
If you asked most blacks that you bumped into...they were there because they’d been with the Army and stationed at Fort Lewis. Other than that ‘magnet’....there was no reason for black population growth in the region.
In the early 80’s, there was no a single black-theme nightclub in the entire region except around Fort Lewis itself.
I do agree with the pricing of property affecting some to leave the area. The thing with the two major national park/forest area (west and east of Seattle-Tacoma) is that it really limits any boom-town or cheaper living accommodations.
During WWII blacks moved to the NW to work in the factories and shipyards..notably Portland.
I was born in Tacoma, lived 50 years in the Puget Sound area...what you say is true, most blacks moved there because of Fort Lewis and McChord...it’s a friendly area, no latent bigotry of any kind. But deeply socialist, and the blacks either self-selected or were herded by real estate into certain areas within cities. It is now a ultra-green area, development of any kind is discouraged...just look at the awful roads...