Capn Bloggs
Not true, although I cannot remember if there is a mention of it in the interim report, but you will get an aural and visual indication of "DUAL INPUT" plus if either pilot presses the "RED" button then a "Priority Left/Right" aural and visual indication as well. So you WILL know if there are dual inputs. So the indications are already there.
As for the "telltale" there is one on the ground to show control input but not airborne, it used to be available during lift off and initial climb, but then some "pilots" were incorrectly being "trained" to use it for rotation rather than attitude!!! An interesting Emirates departure from Jo'burg comes to mind. Airbus then removed the indication at nosewheel liftoff.
To confirm for 1066 the sidestick is visible in the A330/A340. The PM in this case did not need to see it, as he knew they were climbing, from his PFD indications, and that nose up inputs were being made, hence his comments.