Why the Royal Navy was unlikely to capture Bismarck

Did Bismarck's crew realize that the Royal Navy did not intend to capture the ship?

Probably not, but they were unlikely to expect the capture of a resisting battleship anyway.

The answer doubts that Bismarck's crew knew the Royal Navy had no intention of capturing the ship. It also doubts that they expected capture in the first place. By this stage of naval warfare, taking a resisting battleship intact was outside the normal operational expectation. The light-hearted exception about British destroyers wanting to capture anything underscores how extraordinary such an attempt would have been. The likely outcomes were escape, surrender after disabling damage, scuttling, or destruction rather than a conventional boarding prize.