Even if Kim Jong-un is currently at the compound, it does not explain his whereabouts before April 21. He missed the celebration of the 108th birthday of his grandfather on April 15.
This argument does not account for where he was between April 15 and April 21. Also, no other news agencies outside of North Korea have been able to confirm the information spread by the North's government controlled news. This means that North Korea could be covering up actual the location of Kim Jong-un.