Of coarse it's interference. It's however important to get a picture which is correct in all aspects of the phenomenon. QFT resolves also the problem with energy-momentum conservation. Thevsimplified intro-textbook are not really wrong but also not entirely right, and it leads to confusion sometimes. So it's good to havd a completely correct QFT description though it's not a simple one, but I'd not consider neutrino oscillations a simple topic anyway.