Yes absolutely. JEPA is far from the first approach to apply a learned dynamics model to MPC - it's just been well-marketed.

If you're interested, I'd recommend the TD-MPC series of papers, which also learn a latent world model, but achieves much better task performance in general. Unlike JEPA, TD-MPC learns to predict the task reward (what you'd call the cost in optimal control), so it's got a much better ability to rank trajectories during planning.