Can't always pick allies. Heck, some of the folks who were in Los Pepes, and who ripped apart the Medellin drug cartel's infrastructure weren't exactly angels, either.
The MEK could be useful. I'd at least hope someone in CIA or DIA is looking into options on that front.
If they would be, or would not be, useful is secondary to my point, which is that this was not some harmless humanitarian fundraiser.
And given how they were aiding Saddam right up until the toppling of his regime, including in attacks against the Kurds, I am not sure that I can buy the idea that they turned a new leaf.