Halo 3 ODST Sergeant Johnson DLC

343 said they will every dlc for halo combat evolved Anniversary,Halo 3 ODST,halo 3 and halo 4 for free
why can’t I download sergeant Johnson dlc for Halo 3 ODST then?

It was a pre-order bonus, not a paid dlc.

I thought they are the same as regular dlc because they say all dlc will free for these games