You can't use RealID-compliant cards to cross borders anyway, just for TSA and other federal ID checks. You can use EDLs. which are only issued by a few states.

I don't think WA will release RealID-compliant cards, they would have already since, as you mentioned, they implemented other changes to comply with the act like random ID numbers and adding the "not valid for..." text.

Most non-citizens will already have some form of RealID-compliant document, whether it's a foreign passport, green card, etc. Since the only added requirement for EIDs is citizenship, and since most non-citizens have RealIDs anyway, WADOT likely felt there wasn't enough justification to issue 6 different forms of ID to residents.