I've been wandering if grand cruisers can take ship background packages from Into the Storm. Does any know if it is possible or not.

1) does gm say no? 2)if not why not

not directly stated it cant. 'planet bound for millennia' would give an interesting plot for aquiring it

I believe that strictly by Rules As Written, no. However Into the Storm came out before Battlefleet Koronus, and I think that anything a Cruiser could qualify for a Battlecruiser/Grand Cruiser could qualify for.