No, I don’t believe Gabriel gave any revelation to Mohammed. God usually entrusts those kind of revelations to holy men, or at the least, men who receive those kinds of revelations quickly become holy men once they experience the divine firsthand. Mohammed was many things, but he wasn’t holy.
You could certainly be right, but that's not what I'm finding in my study.
Men and women are not chosen because they are holy, but become "holy" through their willingness and acceptance of God and their willful surrender to God, so that He may purify them in His Love. Their transformation is testimony of His Way, how He works and His Love.
Saul is my favorite example, but there are others. Even now, today, living among us in our world, being used by God to speak to us in the language and context we understand.
I think the free will deal God made with us for this test means we must freely submit, freely seek Him and learn His ways, but He won't force us, only welcome and Love us as with the prodigal son. God is not a god of force or hate or war. He is the God of Love and Peace.
I'm sorta late in life and late to the party with my studies and understanding. But, from what I've learned along my path, my guess is that Mo wasn't interested in what Gabriel was selling, if that's what actually happened, and kept his heart encased in stone. His ego had other plans.
Just my theory, but it is supported by what I've learned about human nature and what God and Jesus are all about, and my understanding that there is no peace or love in what Mo gave to the world, just his ego.