Does that prove anything though? Let's imagine a bank is working on this deal; why would they tell a reporter? It's common for companies to deny things to the press even when they're true.
It's Wall Street and there would be rumors if someone was shopping the largest LBO ever. It's not like there are a lot of places you can go for this service, Tesla isn't going to back out on the deal because it leaked your bank has met with Elon.
It's rare for word of mega deals like this to not leak out in some fashion, doubly so after it's already been tweeted about by the CEO. If they had seriously been shopping this deal it would have already been in the WSJ. Considering the letter mentioned no funding I am under the impression that this is more of an Elon solo project and less of a serious undertaking by the company.