No, they didn't add a marker for Areas of Effect on release, although it was on the features request list. There were fierce fights within the community whether to add it or not, because some people thought it would be too "hand holding", immersion would get hurt and it wouldn't fit the game, as a big part of the gameplay is learning, including how to throw fireballs. Others thought of it as a modern PC gaming feature which also fits D&D board game rules, where you can exactly see the range according to hexagon fields and it was suggested to make the feature optional. While not impossible to do within the engine, it got a rather low priority and has never been implemented till now, afaik.