A map editor is possible since the developers must use some tool to create maps for UBI's Anvil engine.
It would mean they may have to make the tool more user friendly and therefore they aren't likely to spend money or time doing that since it really is only a benefit for PC gamers (and they hate PC gamers). I suppose they could bundle and release the best user created maps for consoles as part of DLC.
They have not yet had a map editor released for Anvil games, so it would be the first. Perhaps the engine is to crude to allow this.
It's a shame if they don't have a map editor released since UBI's track record is to give us only a dozen multiplayer maps and then release DLC that just opens up a couple single player maps for multiplayer or changes lighting effects and spawns on an existing map.
Ravenshield and Rogue Spear had strong community support for years due to map editors and 100s of great user created maps.
The least they could do is allow mod support so we could move around spawn locations and objective locations on maps.