I would like to add the ability to silk touch and keep the data of spawners, but nothing I try seems to be working. I instead decided to give the player an empty spawner so they can just use a spawn egg without having free access to a pig spawner in the meantime. I used the following command/nbt data:

/give @p spawner{BlockEntityTag:{SpawnData:

,SpawnPotentials:[\{id:""}]}}

This spawner works fine if placed in creative. It is empty and does not spawn mobs.

The EXACT same spawner ignores nbt data and defaults to a pig spawner if placed in survival.