Netherite items (tools, blocks, armor, whatever) don't burn in lava. This addition, however made it evident that items don't move in flowing lava like they do in flowing water. Until now this wasn't relevant, but now it looks odd when throwing a netherite item into a lava stream.

I don't have a clip of this behaviour, but you can check it out in ilmangos snapshot video at around 11:40.