While I am essentially GTG with what I already own, my major concerns over how I think an AWB in WA will go, assuming grandfathering (I really don't envision outright outlawing of possession just now):
1. No more parts
2. Severe limitations on use (this includes standard mags). 'Authorized' range or within domicile. Also includes transportation restrictions.
3. Storage
4. Impacts to non-'military' weapons - WA's definition of 'assault weapon' became the broadest in the country under 1639 IIRC
1-3 are where civil disobedience will play in.
ETA took a screenshot of that KOMO poll's results - as stated by others, not that it matters, but will still use it as an artifact when contacting reps.
Also, if this goes down the initiative path, any signature gatherer that crosses my path will get the same message: "You already had 1639, you had a magazine ban. You have more than enough - NFW am I signing that."