Microstrategy's Orange Decentralized Identity (DID:BTC) project is basically DID:ION, but it stores changes to the DID Document JSON as an OP_RETURN in the blockchain itself instead of on IPFS. 

There is a coding scheme to declare changes to existing JSONs and store them as new spend transactions. The DID:BTC:<address> references the creation event. To reassemble the complete document, follow all spends and apply each change to the DID Document as specified. 

It's cool that it is decentralized, but this is like Ordinals. The use of the chain for every change can be quite data-heavy. 

The funniest thing is Microstrategy demonstrating the use of DIDs to sign regular e-mails. Once you use DIDs to sign/verify, you can use any other DID method, including DID:NOSTR or DID:MYCOMPANY. They are all equally "decentralized". :) 

What Saylor clearly doesn't understand is that DIDs are already decentralized by definition. Adding a blockchain method doesn't make it more decentralized. The user's choice of method is the decentralization feature (like choosing which relays you want to use).