I would say it's nothing more than a rumour.
Being the referred orange LoCo so conservative and with so much still to optimize and take advantage in intra-european flying I don't see them going Long-Haul anytime soon. That being said, I'm not saying they are not looking at (and probably in deeper studies) the possibility of introducing a widebody fleet or using the 321neo on longer routes, but I would say that at the most they would be on a study phase only.
There is still so much money to be made in Europe and with the A321neo equipped with 235 seats the constraint problem may have been deflected already. Bear in mind that at the moment the talk among those supposedly in the know is that we may already have overcapacity in Europe...
Currently pairing and rostering is a (fairly) easy task and the company can optimize the use of their crew and aircraft as well as adjust between winter and summer schedule fairly easy. Going Long-Haul will bring an array of complexity to the system that may only make sense if there is nothing more to do in Europe, and at the moment I see a lot of money to be made in Europe.
Further to the above, with the network the orange teams has set-up they can made 5 or 6 sectors each day with each aircraft on most bases - let's say that would be 1000 tickets sold. On the same time frame an A330 would only do 2 sectors (or less) - even at a high density configuration, the A330-900 would only be able to transport 700 pax. If you consider the delta on leasing an A321 compared to an A330 and add to the equation the current pricing of a transatlantic flight it is fairly easy math to say that the money is probably better used in leasing the A321s to deploy in and within Europe.
Cheers.