Is the path in white considered the most likely?
No; it's a bit complicated to explain.
All of those tracks are from one model; the white is the "Operational" GFS; the other tracks are "ensemble" members - they are the same model but with the initial conditions "perturbed" a little bit. It's a bit of the "butterfly effect." We never actually know the true current weather conditions everywhere, so the perturbations show what happens if things start out slightly differently. The ensemble tracks show that actually it's probably more likely it curves back to hit the US, because most of them do, and that the "operational" track is probably less likely.
That path is representative of the GFS computer model, which the hurricane center has relied upon most as the basic for their track forecasts. However...that's also the model that is being questioned the most outside of the NHC due to specific "quirks" it has in resolving certain technical interactions between competing storms - which I'm not qualified to even attempt an explanation about.
Ennyhow... that's why the European weather model is being cited in the original post. Other models (as you see from that first map) are also jumping on board with the idea that this hurricane will be "captured" by the next approaching storm front. That scenario is now being seen as more likely than not. Even the NHC is now admitting that with this post on their most recent 'Discussion' page:
"OVERALL MORE OF THE GUIDANCE HAS BEEN TRENDING TOWARD SHOWING MORE INTERACTION WITH THE EASTERN U.S. TROUGH LATE IN THE PERIOD."
...and they cited the Euro model as proof. So all interests in the US NE should keep a close eye on this.