I don't think there's anything wrong, because this is just an assumption or prediction that is made. Maybe I would say it's wrong when someone claims with certainty that Real Madrid will retain the La Liga title and also the Champions League. If it's all just an assumption, then I think it's valid.
You're right that they're not as consistent as last season, but they still have the potential to be more consistent. The opportunity is on them, it's just a matter of how they can be more consistent.
In a prediction, we can't say it's wrong or right, because what is seen is the result of analysis, so it could be that it doesn't happen and it could be that it happens.
I was wrong, the assumption could be anything. You're correct that except the person says it is certain that it will happen it cannot be disputed. Real Madrid is still competing for both trophies which means they can be fortunate to win both. If they can be consistent in their performance from henceforth, they can achieve it, after all they have enough good players.