The BA MSL is not in DoJ order in a number of areas for a number of reasons. DoJ and seniority are not inextricably linked. The bmi pilots who join under a TUPE transfer will maintain their bmi DoJ for anything that uses a DoJ for reference.
The question referred to DoJ, so that answer was given. Unfortunately, some people seem unable to focus on anything other than their position on the seniority list, regardless of what it brings them. This is rather unimaginitive, rather short term and rather sad.