I love the Wachowskis, but it's hard to imagine where the Matrix story can thematically go from here. The first was a neatly self-contained story about empowering oneself through choosing truth over comfortable ignorance, and breaking free of the mechanised nature of modern life. The sequels turned all the original's themes upside down, considering ideas about controlled rebellion as a mechanism to stabilise systems of power, about the intersection between choice and predestination, and how opposing factions trapped in a cycle of conflict mirror each other to the point of transcendence. Although their execution, sequels especially, was wildly inconsistent and frustrating, the trilogy (whether or not the sequels were planned originally) is remarkably cohesive and rich on a thematic level. Neo dies at the end because he has broken the cycle, transcended above karmic cause and effect, and all the other stuff that makes you sound like a prick when writing about it on a videogame forum.
Cutting the crap, his story's complete and by proxy, so is the story of the Matrix as we knew it. I suppose there might be some dramatic interest in the question of what happens to everyone else, machine and human, beyond that point, when they basically have to live with the foundational structure of their existences being torn down, but doing another 'man vs machine' conflict would undermine Neo's sacrifice completely, yet that conflict is at the core of what the Matrix is. The Wachowskis, for their undeniable faults, are never short of imagination though, so perhaps they'll spring a surprise. Can't say I'm hopeful: relaunching old properties, particularly ones with such a definitive ending, almost always goes badly, and my suspicion is that if the Wachowskis are involved, it's either because they need a hit after the Jupiter Ascending debacle and Sense8's cancellation, or they've agreed to participate to try and minimise the damage of a studio which was going to proceed with making more Matrix movies regardless. I'd be pleasantly surprised if they were genuinely inspired with more story to tell in that 'universe'.