I know they did not just make me download a DLC I probably won't even purchase

this ridiculous shit needs to stop

Since the new DLC includes a couple new biomes, and a 14-mission scripted campaign (as in, not procedural like the bulk of the rest of the game) , that will account for the bulk of the update.

While it is including the DLC assets in the update, this is actually PGI being relatively generous to the consumer, most other games would require everyone in multiplayer to have the DLC (here, only the host needs it). Though 20 USD is definitely on the high side for the advertised feature list.