No way could they have burned alive! If they had, I would have been as upset---perhaps MORE as when Mufasa died!
Yes, I really love the hyenas.
Plus they didn't deserve it. They were funny villians.
I believe it was officially confirmed that they survived in an old interview. Sadly, no one knows about that interview, hardly. If they had appeared in the sequel, or been shown after the battle in 1.5, we wouldn't be having this discussion. Sadly, they did not.
I consider the series canon, and consider it as proof that they survived. Sadly, no one else is considering it canon.
I hope if a 4th movie is made, it will be about the hyenas. I really love them, and think they deserved to be in 2, and in movie 3 wayyyyy more. They had two scenes, unless you count the scene where Pumbaa gassed some hyenas who may have been them, or might not have been.
But they definitely lived. Someone I asked this said, "Whoever says they didn't deserves to get bitten in the butt by Shenzi!"