Autothrusters will be the reason the Phantom dies away.
It's a great ship and it has some really interesting builds. The problem is that it has an obvious 'optimal' build that's so much better than anything else.
But there's design space there for the Phantom to move around in. For 4 more points than an X wing, you get +1 Attack, -1 Hull, +1 PS, no Target lock, but Barrel Roll, Evade, Cloak actions and Crew and System upgrades.
KineticOperator's Six Sigma list is an example of a place Phantoms might move towards.
The only reductions we'll see in Phantoms is specifically the Whisper + ACD + VI + FCS builds we see all the time.