Sure. San Jose is not Seattle. Nor S.F. but, Seattle has massive presence in FAANG doesn't it?
I'd be interested if the % varies for Microsoft and Boeing: that might show if the effect is out of scale.
There's also a long tail effect of hiring staff from x who gain seniority and then hire staff from x because it's a known quantity.
And with a massive ICT sector people from UW can cut their teeth in junior roles close to home after graduation, get their chops and then swing into FAANG with good credentials and experience behind them.
MIT and Boston might be similar.
Guess which university close to the seat of government (cough George Washington uni) has an amazing track record of placement of graduates into think tanks and lobby groups...
UW is not one that easily comes to mind when one thinks of getting a job at a FAANG. Looks like it should be at the top of the list if a job there is your goal.
https://docs.google.com/spreadsheets/d/16dDaOHI5KJb_tO_iHXBP...
Also, I suspect Microsoft has been a great contributor to the school. That's another reason it does so well in CS placement.