Minecraft wiki entry for Log, associated text: In Bedrock Edition, dark oak and acacia logs share a block ID separate from the old logs, called log2, because all the other data values on the previous log block were occupied by rotated variants (red sandstone slabs suffered a similar fate). There are still 8 remaining data values on the block that cannot be obtained. This was also the case in Java Edition prior to 1.13.
Even if stems or their plank variants cannot be used as fuel or made into charcoal, the player can bypass this by crafting them into crafting tables or sticks, which can be used as a fuel.
Crimson and Warped stems are the only logs that have an animation.