SPOILER ALERT. If you don't want to know about the end, don't read any more. Alright. So after juicy bath soap glowy Ghaul gets killed, it seeems to me like there's nothing for a raid to be about. The only thing I can potentially see is the whole "the taken are crowning a new ruler" aka Savathun. Also the ships in the end cutscene. Do we know what race those ships are from? Maybe vex? The light awakened them, so for some reason I'm tempted to think it's the hive. That and the taken seem like our only options. The consul is dead, so is Ghaul. What major objectives are there left to accomplish that we haven't done in strikes or adventures?
1) There's a decent chance that those particular ships are the Darkness, or at the least it's prime agents (Think what Guardians are for the Light). 2) It's possible that, in light of the ending, either the Consul or Ghaul himself could yet live, and either a) claimed the Leviathan, or b) otherwise become a VERY big threat. 3) Could be that we're facing other members of Ghaul's coup, and needing to rescue the proper Emperor of the Cabal.