Whenever Hashem is angry, there are repercussions. How come that no repercussions are mentioned here?
Rashi (citing the Gemara in Zecvachim): They are hinted here in the following words "ha'Lo Aharon Achicha ha'Levi?" 1 - which intimate that he would now replace Moshe in the role of the Kehunah.
Ramban: Refer to 4:10:2:3*.
Rashbam: The ramifications appear only in Pasuk 24, where it says that an angel wanted to kill Moshe.
Why does Hashem refer to Aharon as "ha'Levi"?
Rashi: Because Aharon was supposed to be the Levi, and Moshe, the Kohen. But now, he would become the Kohen, and Moshe the Levi. 1
Seforno: If anybody other than Moshe was worthy of being sent, it was his brother Aharon, who was a gifted speaker 2 and who was undoubtedly wise, like all his brethren the Levi'im.
Why did Hashem see fit to tell Moshe about Aharon's reaction to the news that Moshe had been chosen to lead Yisrael?
Rashi, Ramban and Seforno: Contrary to what Moshe thought; not only was Aharon not angry at Moshe's appointment, but he would go out to meet him 1 and would rejoice in his appointment upon seeing him. 2