You have to realise when a pilot makes a decision to leave, it takes several months to secure another position.
I have noticed in the last 6 weeks a massive change in sentiment with the expats. Nearly all of them are either leaving, in Interviews with other Airlines, have applied to other Airlines, or are at the very least talking of leaving. It wasn't like this before (certainly wide body).
So your "mass Exodus" whatever the term implies, will be evident within the next 3 to 6 months. That's my guess anyway.
If TK fix the salary, it may go some way to block the leak.