Everything said by the other posters was right, and as I have quoted prior, they re-created the Classic realms after moving all Vanilla realms to TBCC.
You were moved from your Vanilla German, to a TBCC German, which got retired to a default English realm here in preparation for Wrath. I’m quite sure, it was Celebras?
So the Classic Celebras now, has no relation to your current toons.
Edit: Since OP did not mention which realm it was (Dragon’s Call) everything still lines up with the realm consolidation thread mentioned there.