It has been a long time without publishing any ratings now. There are multiple reasons, but one is that updates of the underlying database have been neglected. Currently, some work has been put into adding data from newer matches, and while the database is not as complete as it used to be, an attempt has nevertheless been made to produce an (almost) up-to-date list of the 100 top players. That is, there may be some players missing due to playing in a league that has not been updated properly, or due to not having included any recent international matches.
So, what is up with Messi at 24th? Just age, it seems, as the performance is matching very well the expected development: