There do not seem to be claims of the latter therefore it could be confined to signature campaign participants only.
There's not a single withdrawal from the multisig address after the 9th of August. How do you say this? No one claimed? No one claimed because it's a matter of 5 days and possibly, most of them have deposited to enjoy the mining reward whirlwind offered. Check out their multisig address, no withdrawal since the 9th of August. It's definitely a flag unless they solve the issue faster. Check what decodx said.
if there would be an exit scam, it would be trivially easy to fake losses to claim back the escrow as a victim.
Even if MJ has the fund in escrow, I don't see how he would be able to utilize the fund to compensate any victims. The amount in question is far higher than the amount in escrow. If I can remember correctly, there were 6+ Bitcoin initially in the multisig address. They may have added more in the pool but who knows? If it's a scam, we can assume that it's more than 5 BTC + additional if they already have removed any funds. The amount in escrow won't be even close to compensate the scam (keeping aside how will it be done).