In December, Musk indicated that the company would start freeing the namespace of 1.5 billion accounts soon, although no public announcement of that freedom has been made. Worth noting, DemandSage indicates that as of 2023 there are only 1.3 billion Twitter accounts on the platform as a whole, with only 237.8 million of them active daily.
Twitter set to be the first ever platform with -200 Million users!