On Dockyard, to be able to repair the EV for the first time, there is a secondary objective : Close the gate. It take some times to do, especially while attackers push here. But a Javelin in defence just need one rocket to instant re-open it. And she can do it at defence side!
Same in Trainyard, it take some times for attackers to close the gate and then plant. But now Javelin can instant open it (it was already possible with Arty/Kira but it take a bit longer and require some knowledge about the map).
It make this secondary objectives totally useless and mostly ruin the chances for attacker to complete their first objective.