It doesn't really back up the fact about a reduction then if they did it last season and they get the same.
Depends, you can't really measure how many wouldn't have renewed if the prices had stayed/increased so its difficult to say if its a success.
For example after the garbage served up in 14/15 season under Pressley at the Ricoh I had genuine fears we would be averaging 6-8k for the following season. But we've averaged 12,500, now we have people saying the increase wasn't enough to justify the reduction. You're going on the assumption that if prices had stayed the same then pretty much everyone would renew and attendances would stay around the 9-10k level they were the previous season. Given how shit the season was I'm not sure that is a safe assumption to make.
Its the same logic applied here for Sheffield Utd, they've been in this league even longer than us and had a very disappointing season, they have secured there lowest league position in league one since relegation. If Sheffield utd prices had remained the same for the upcoming season, can you guarantee sales would have still been 11,500? I don't think you can but there is no way to prove it either way.