I hear what you’re saying, I really do. However, you can’t compare this directly with the Moray GR4 collision.
This happened in the visual circuit at night. I can’t speak for Lossiemouth SOPs but there’s every chance they would squawk standby in the circuit and if not they certainly would not be reliant on TCAS at that stage of flight.
Notwithstanding this, your argument about CWSs on fastjet aircraft is still valid.
BV