This is one of those rare cases where the answer actually feels pretty clear. If the flight is AA operated, same availability, same price, and the onboard experience is identical, I’d have a hard time giving up Alaska miles.
Alaska miles still feel more “special”. Harder to earn, fewer transfer options, and they tend to shine on Hawaii and select partner redemptions. AA miles, on the other hand, just keep getting quietly devalued and pushed into fully dynamic pricing. Feels like a use them before they get worse situation.
For a PNW family, Alaska miles are just more flexible long term. Hawaii alone is a strong reason to protect that balance. AA miles are great for South America, but if that trip is only a maybe next year, I’d still lean toward burning AA now and keeping Alaska for when it really matters.
Nothing is truly safe