I think if they casually shared it, you could ask what they mean by hyperlexia and what they see, and if it doesn't fit, gently guide them to see what you see.

I've seen preschoolers labeled with hyperlexia because "nobody reads at this level". But at 5, I'd think it was a lingering thought or it may even be that he decodes well above his comprehension level, and just needs to keep addressing comprehension. (aka a difference, not a disability)

The issue in my mind is if they've labeled him in their mind and if that label is incorrect, resulting in academic teaching that are not at his level. Unless that's happening, I wouldn't be concerned