Uft, imagine if that happened and musk chose a single unicode character as the domain?!
Unicode are already sanitised from domains, because there are ubicode characters that look like - but are distinct from - ascii characters… which opens a huge pandoras box of MITM attacks of malicious sites on domains that visually look the same as legit domains.

If musk wants a single unicode character, all the browsers are going to have to figure out that can of worms