Hi! Yes, they are available online. But I don´t know if it will increase the chances to find online activity.
The is: You can´t use the DLC-ships online...that really sucks.

You could call someone out for an online match, there are some skilled Pulse pilots out there!
I still need a pause from Pulse because Outpost 7 Black was driving me mad...but I´ll be back some day.