Minecraft wiki entry for Leaves, associated text: Occasionally, leaves grow through other blocks, acting as though they are still connected to the tree. They may also completely replace blocks they try to grow into.
Leaves do not prevent chests from being opened.
Some trees seem to occasionally drop apples or saplings without being destroyed due to creation of leaf blocks not supported by logs.
The frost texture in Bedrock Edition is not an instant transition. Instead, the leaves slowly shift from their original color to the frosty one.