easy job for one dev. ask any modder how long it would take them to make one shit map without much detail. take in mind that modders do this in their free time, so actual dev could do this in fraction of time.
most of aprils fools models are imported from WT. only thing they need to create is models for infantry and depending on their tools this could be done relatively fast.
this is just changing one line of code in physics engine. you could change gravity in original half life which is 27 year old game from console, not to mention modern games
not that i dont agree with you that they are too slow with their updates, but it is usually more than just handful of weapons.
that is why i wanted to get clarification from mcdonald about terminology. i am assuming that frontline will probably be new faction matchup (e.g. soviets vs japan or french vs germany). battlefields are currently both campaigns and maps in old system.