If Politico is right, I'd say that's a pretty safe indication that Elizabeth Warren is not running. That's not the kind of thing a sitting senator wouldn't mention to the presumed nominee:
Hillary Clinton, expecting no major challenge for the Democratic nomination, is strongly considering delaying the formal launch of her presidential campaign until July, three months later than originally planned, top Democrats tell POLITICO.
The delay from the original April target will give her more time to develop her message, policy and organization, without the chaos and spotlight of a public campaign.
A Democrat familiar with Clinton’s thinking said: “She doesn’t feel under any pressure, and they see no primary challenge on the horizon. If you have the luxury of time, you take it.”
Advisers said the biggest reason for the delay is simple: She feels no rush.
“She doesn’t want to feel pressured by the press to do something before she’s ready,” one adviser said. “She’s better off as a non-candidate. Why not wait?”
A huge advantage to waiting is that Clinton postpones the time when she goes before the public as a politician rather than as a former secretary of state. Polling by both Democrats and Republicans shows that one of her biggest vulnerabilities is looking political.