The last time I heard one of our managers discussing the issue was only recently, and his view was quite definative.
Whilst it was mentioned there had been a 'degree of misunderstanding' by someone in the CAD, and this may have been due to a doors issue, CX were still believing it would be able to plan for crew to operate both 330 and 350 as a common type.
If this recent news above has superseded the previous doors issue, then that certainly throws a substantial spanner in the works with regard to future 'bus crewing levels.