Even though the Phoenix trilogy is pretty much over, he's still going to play a major role in the Apollo trilogy. And that arc still has some life left in it, it just didn't have a well-executed start (case in point: Turnabout Serenade shouldn't even have happened due to the sheer amount of idiocy went into convicting a ten-year-old. Then again, this is the Ace Attorney police force we're talking about...).
So yes, it should continue, but with the Phoenix arc all wrapped up nicely and topped with a bright red ribbon, it'd be foolhardy to open that case file again.