Well that's the thing - the reason I don't think this theory is too far fetched is because I don't think they've chosen Tom to spread disinformation, I think their intentionally using Tom because he accidentally got close to something and they wanted to avoid him letting something out.
Say he did meet with Podesta, and he mentioned something dumb he'd picked up on his conspiracy channels that was actually very close to something true. Maybe Podesta, or someone else Tom had contact with, passed along the potential threat to Tom spreading that kind of information.
If they saw him and his potential audience (he does clearly have one, not a large one but it's large enough to be potentially damaging) as a threat, then maybe they would give him a couple of meetings with semi important people, get them to rile him up, and then let him loose to say absolute rubbish.
I'm not saying it's the truth, and it's definitely a bit of a spectacle just to shut him up, but I think it would make some sense - and to be honest it's a nicer alternative than Tom is just a scam artist.