This is just not true. Check out the analysis here [0], for example. His rating improvement has been steep but he's also played a very large number of games, so his rating gain per game as opposed to per unit of time is not so crazy.

Also, no one seriously expects Hans to be a world championship contender.

[0] https://www.reddit.com/r/chess/comments/x9bgtx/how_quickly_d...