It always worked like that, for furnaces too as exemple...
For the item :
/give @p minecraft:iron_hoe{Damage:1s}
For the spawner :
1) /setblock ~ ~-1 ~ mob_spawner
2) /data merge block ~ ~-1 ~ {RequiredPlayerRange:0s,SpawnData:{id:"minecraft:armor_stand",ArmorItems:[{},{},{},{id:"minecraft:iron_hoe",Count:1b,Damage:1s}],CustomName:"\"TEST\""}}
The same for me. Confirmed
Confirmed in 1.13.1.
NB : This bug also affects every transparent block with a "full face" like stairs, snow...
NB 2 : If it's intended to work like that, it is very "map breaking"