A recent Reddit thread has questioned whether or not the 4-move meta may be changing in Generation VII with the release of Pokémon Sun & Moon for the Nintendo 3DS this November.
The image comes from E3 and shows the new summary of a Pokémon’s current moves, but the background striping seems to suggest that there is an extra slot. This is not any sort of solid indication and could simply be a striped background which does not align with the data, but with the way in which Tackle lines up it does give fans pause. It should also be noted that Professor Kukui is studying Pokémon moves, a foreshadowing of something new we may see.
Obviously this would have huge implications for competitive battling and many Pokémon that have found themselves too limited by the four move standard could have room to shine.