^ Not likely. All Picard said in the episode with Guinan was that the E-C was lost near Narendra 3, defending the Klingon outpost from the Romulans, and presumed destroyed. But what I want to know is why the Federation didn't declare war on the Romulans for this incident. If they had any kind of evidence that Romulan forces had destroyed the C, it would be a cause for war between the Federation and the Romulan Empire, current (in 2344, that is) difficulties with the Klingons not withstanding. And any Ent-C survivors popping up in the aftermath, whether at that time or years later, would have no reason NOT to tell their tales of battle with the Romulans. There would be no reason that I can see for survivors to stay hidden.