This may not be intended, since this item is otherwise unobtainable. (using shears on double-tall grass just gives you two grass items)

Steps to Reproduce:

1. Give yourself a chest with the "minecraft:chests/village/village_savanna_house" loot table:

   /give @p chest[container_loot={loot_table:"minecraft:chests/village/village_savanna_house"}] 1

2. Place down the chest, open it and look for tall grass within it.
3. If you found no tall grass within the chest, repeat the above step until you do.
4. Take note as to whether or not tall grass can be obtained through chests within villages.