I believe He was addressing the Apostles, not the disciples.

Matthew 19

28 Jesus said to them, “Truly I tell you, at the renewal of all things, when the Son of Man sits on his glorious throne, you who have followed me will also sit on twelve thrones, judging the twelve tribes of Israel. 29 And everyone who has left houses or brothers or sisters or father or mother or wife or children or fields for my sake will receive a hundred times as much and will inherit eternal life. 30 But many who are first will be last, and many who are last will be first.

See also Luke 22:25-30.

The twelve tribes, the 144,000, and other references are symbolic of the faithful, the new Israel, and the Kingdom to come.

The same type of language is used in Galatians 6:16, James 1:1, Romans 9:6, Romans 2:29, and elsewhere.

Jews were used to the symbology and knew exactly what He was saying.