Our Airbus manuals nowhere state "Do Not Turn". They do emphasise not to Mvre based on the TA, but to use the TA to visually acquire the traffic. What's the point of visually acquiring it if you are not allowed to avoid it
In the event before/after a TA I visually acquired a threat, and time/RT traffic etc. prevented a timely ATC co-ordinated, separation I would consider a turn as required - after all, assessing/achieving visual lateral separation is relatively easy.
If an RA results, then you have to follow the vertical guidance, of course. If it became perf limiting (unlikely) then any AoB would have to be rolled off.
We need to keep an element of commonsense here... TCAS is a great aid, but we still have eyes and ailerons
NoD
Edit for spelling