All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
Seeing the Prophet in a dream is possible, and whoever sees him in a manner matching his real shape in which he was created, then he has indeed seen him, because the devil does not appear in his form (i.e. can not take the actual form or appearance of the Prophet ).
For more benefit, please refer to Fatwa 84858.
The Prophet may inform the person who sees him in a dream with something that may happen, or that he orders him to do something and so forth. However, he cannot order him to do something as a legislation, like what is mentioned in the question which is specifying the recitation of this Chapter with a given number of times, because the legislation stopped by the death of the Prophet ; Allaah Says (what means): {This day, I have perfected your religion for you, completed My Favour upon you, and have chosen for you Islam as your religion.}[Quran 5:3]
Therefore, this man is either a liar or a magician or a juggler, and this is what is predominantly thought about him, or that the devil came to him in a dream and told him that he was the Prophet and ordered him to do what is mentioned. For more benefit, please refer to Fatwa 18129.
Finally, it should be mentioned that there are many claims about seeing the Prophet in a dream and that he had given the person who saw him instructions to do a certain type of mention of Allaah and so on, and then the person who saw him in a dream considers this as a legislation and he orders his followers to do it, as it may happen to many Sufis and their likes, so one should be careful about such people.
Allaah Knows best.