DVD/BR release dates are now known, both here and America... but for some reason, it will be released digitally some two weeks earlier.

March 19th - digital release (might just be in America).
April 2nd - hard copy release in America.
April 3rd - hard copy release in Australia (according to the JBHifi website)

The contents of the US combo pack that might be released here as well, with these bonus items...

BONUS FEATURES ON 4K ULTRA HD COMBO, BLU-RAY COMBO & DIGITAL*

  • Sector 7 Archive
    • Agent Burns: Welcome to Sector 7
    • Sector 7 Adventures: The Battle at Half Dome (All-New Motion Comic)

  • Deleted and Extended Scenes
  • Outtakes
  • Bee Vision: The Transformers robots of Cybertron
  • Bringing Bumblebee to the Big Screen
    • The Story of Bumblebee
    • The Stars Align
    • Bumblebee Goes Back to G1
    • Back to the Beetle
    • California Cruisin’ Down Memory Lane

I like that they have included Deleted and extended scenes, as it gives us a look at some of the earlier workings or ideas... or painfully teased with something that we would have preferred have been included.