I haven't read any such statement, and the above link conflicts with that claim. I don't find it odd at all, they would lose FOM TV money with the name and they would lose potential future sponsors who probably do want to buy into the Lotus name.
Running a pay driver for 30 laps doesn't really say much. Its no different to running Vladimir Arabadzhiev or Rodolfo Gonzalez.
Lets also not forget that they are still a small team, with a relatively small budget. Even if their main budget is covered, attempting to acquire more money is not really surprising is it?
I'm also a little cautious about reading the various "statements" being made currently by both sides of the Lotus argument, its hard to tell which one is telling the truth and I really don't care that much. If Fernandes did say that (that his companies would leave), its most likely rubbish made up to excuse the money demand. But, as I said, I haven't read such a statement and I'm not so sure I believe everything either side says. (although I'm more and more inclined to believe Fernandes' side when Proton keep contradicting themselves).