I think there could be an option 4 which is more likely happening in my opinion.

Option 4:
Amazon is enabling deposits from various crypto currencies in a way they currently do with fiat money. So you'll be able to charge your account with credits and then buy stuff at a real-time rate.

What do you guys think?

agree @Dennis - converting various cryptos to local currencies at daily spot rates is surely most likely, if anything... watch out for the "Coinbase effect" they day they indicate which :).

I'd rule out #3... given the tightrope they are walking already with governments crying monopoly, addition of their own currency would only create trouble. Though your crypto-libertarian says this ceases to matter on a long enough timeline!

Rather than a broad consumer-focused currency, I wouldn't be surprised to see them dip a toe in with AWS, and launch some sort of FileCoin hedge... i.e. private chain (Ripple-esk) token designed to provide access to a more, but not fully-decentralised EC3.