Flamethrower verse Gaviota

He meant replace as in he put the skill over his grenade button.

But Yes:
Burst fire is a "boost" to Double Shot.
Wraith of the octopi is a "boost" to Octopus.
You can still summon gaviota and air strike separately.

oh lol. we were talking about it in-game and couldn't figure out why he would say something like that when everyone else was talking about skills actually replacing eachother. o_o;