If I pre order a physical copy of the pc game and get it at midnight Eastern time. Will I have to wait until it is realesed on steam which is 4am my time?

Probably due to the fact that the physical copy will not have all the files on the DVD - you will need steam for the
Remaining files for the game - I don't know if you can preload the DVD or not but you will have to have steam
Finalize the game

"Release Time

Want to know exactly when you can start playing Fallout 4? Digitally the game will become available at 12:01 am (local time) in all territories (In North America, the unlock time will be 12:01 am EST), except Asia (available at 12 am on Tuesday, November 11th) and Japan (available at 12 am on Thursday, December 17th)."

Yes, because the disc version still installs it into Steam, where the game will only be "released" at that time.

you can still have it installed completely before 4am, just can't play it till it unlocks.

It won't be installed completely. Just 99.9999% of it installed.

If it makes you feel better I bought the Pipboy Edition and I won't have it until 4 PM Eastern on November 10th.