Numbers 12:6

‘And he said, “Hear now my words. If there is a prophet among you, I Yahweh will make myself known to him in a vision, I will speak with him in a dream.'

Firstly He confirmed what a prophet was. He was a man who received visions and dreams. That, said Yahweh, was how He made Himself known to the general run of prophets. Both of them probably knew something about that, so, yes, they were prophets. He acknowledged that. But how different they were from Moses.