According to Mass Effect lead writer Mac Walters, the next game in Mass Effect series will have nothing to do with Shepard "whatsoever."
Bioware and Mac Walters are going to lengths to distance the game from feeling like an epilogue or a spinoff of the Shepard trilogy. The game is not named yet, but the team is adamant that we shouldn't call it "Mass Effect 4." It will take place in Mass Effect's rich universe, but it will be a 100% "without the Shepard character or the Shepard specific companions."
Walters also assured that he has learned his lesson from the Mass Effect 3 ending controversy – even though he is still satisfied with it.