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:
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).