Note: There has been some confusion on whether this is a feature request or a bug. A previously reported bug for Java Edition, MC-118095, was closed as working as intended. Mojang Support has also pointed to a post on the feedback site when contacted directly. As there has been no official statement on whether this is a feature request or a bug, it is unknown if it is a feature request or a bug. If the issue is closed as working as intended, then please move all attention to the feedback page post (linked above).

If you break gravel with a tool such as a shovel, the gravel has a chance of turning into a flint. However, if you drop it on a non-solid block such as a torch, the gravel will not turn into a flint.

Steps to reproduce:

1. Place a non-solid on the ground (such as a torch)
2. Place a solid block above it
3. Place a large tower of gravel above it
4. Break the solid block to let the gravel fall on it

Expected results:
A mix of gravel and flint drops should be around the non-solid block

Actual results:
There is only gravel