FWIW, David T's post here states that Bismarck supported the annexation of Alsace, just not that of Metz:
France Keeps Alsace-Lorraine but Loses its Colonies in 1871
There was never any real possibility that a victorious Prussia/Germany would not take *some* of Alsace-Lorraine. The question was how much. "The annexation of Strasbourg and of Alsace appeared to him [Bismarck] necessary in order to enhance the security of southern Germany and make any French...www.alternatehistory.com
Interesting thanks. It sounds like while he had doubts about some of the annexations he went along with it as a quid pro quo for political concessions by the army. Not what I'd heard before but opinions and viewpoints change as new info becomes available.