Yes and no. Assuming that time machine backed up
the movie, and assuming that there is still blank space on the time machine drive, it will stay there.
However, once the external drive fills up, the oldest content on the time machine drive will be automatically and systematically deleted from oldest to newest
Yes they will be backed up on your Time Machine provided you have not excluded them from doing so in the Time Machine preferences. The problem is that Time Machine is a backup program and it was not intended to be used as a store and access backup. >
http://support.apple.com/kb/HT1427
What you really need to do is pickup a second External HD to store and access overflow files that you want to remove from your Internal HD. Then have Time Machine backup both your Internal and the External HD with the overflow files.