Not the dev. If he dumped, he did so weeks back when he was more active here, and when enthusiasm and the price were higher.
Everyone who holds MAR is now at the mercy if he really is continuing to work on this project. All holders can do is hope it is just a summer break.

One thing is true what stompper said, no would or should buy MAR now. Hold, yes. Sell, maybe. Buy, no....
MAR dev could prove otherwise by providing a roadmap or at the very least giving a date when work and activity will pick up again. Not a broad two month time frame 30+ days away.