I need to execute code when my block is destroyed but before its tile entity and state are removed. I need this because I need to replace the block with other block, and the data required for this is spread across the blockstate and the tile entity. When the code is executed the getBlockState and getTileEntity methods of the world object must return the correct blockstate and tile entity of the old block(not the new one that the old block is replaced with).

overwrite onReplaced in your block class and call super after your code