I don't think it's necessary, but I think usage will gradually shift over a few years towards it.
I just hope they justify it with making the next Codex: Space Marines instead be Codex: Adeptus Astartes. I mean, with Adepta Sororitas rather than Sisters of Battle, and Astra Militarum rather than Imperial Guard... their excuses for not switching Space Marines over are beginning to run a trifle thin. If they embrace the gothis pseudo-latin wholeheartedly rather than a bit here and there, though I'll accept Astra Militarum more quickly, I think.
What sphinx of plascrete and adamantium bashed open their skulls and ate up their brains and imagination? Imperator! Imperator!