You can't rule it out. As soon as there's a drop, however small, it's going to be a news story with an attempt to explain why gates have gone into reverse, with the negative aspects of the game inevitably highlighted and potentially encouraging the people who only jumped on the bandwagon in more recent times to jump back off again.
We could be looking at something similar to population growth, which is increasing now because people are living longer but is predicted to collapse due to younger generations not having kids. I've heard/seen people claim the genuine football fans that stick with their club through thick and thin are now much older on average and the extra bums on seats are because those men who traditionally turned up on their own or as father/son are now bringing the whole family along who spend much of the match looking at their phones and therefore won't be so inclined to continue the tradition once the older dyed in the wool types have climbed that additional staircase into row Z of heaven.
That's a theory which may have some sound logic behind it, but you can't underestimate the power of media hype. As long as they're making money off the back of the game and relentlessly pushing football as one of the most positive and meaningful aspects of secular life that brings communities together, then high attendances can probably be maintained for the foreseeable, at least until the super league happens.