There’s a general rule I’ve heard before, which is, in the simplest terms, “Never leave a submissive alone.”
The context of the rule was actually a scene involving bondage, but I think it applies in a broader sense. It’s well established that most submissives are quite demanding of attention. There is nothing wrong with this. In fact, I quite enjoy that quality. Given that fact, I personally believe the “silent treatment” not to be a punishment at all, but rather either a cop-out, or possibly treatment bordering on abuse.
In some cases such a “punishment” could actually be the Dominant attempting to escape responsibility. This is never okay. A Dominant should have the strength to maintain his responsibilities no matter the circumstances. He may need the help of his submissive, which could actually serve to be a great bonding experience, but he should never abandon his responsibility for any reason. I’ve seen more than one occasion in which a dominant all but abandon’s his submissive because he’s dealing with things in his life that he believes he is better off handling alone. There are aspects to this that may be true, but it is in no way an excuse to cut off contact with his submissive.
It also may be the case that the Dominant actually believes this to be an acceptable punishment. If so, he is just plain wrong. It doesn’t matter what kind of relationship you’re in, cutting off contact with your partner, in 99% of cases, is never acceptable. Nothing can ever be solved by an intentional lack of communication. If anything, it can only do harm. In a situation like yours, leaving someone guessing about what they’ve done goes beyond punishment, especially with someone driven to serve the other. This, in my mind, is bordering on abuse. These exact kinds of tactics are the kinds of things that abusers use to control their victims. Even if there are no such nefarious intentions, this kind of behavior is absolutely unacceptable.
So to answer your question directly, no, the silent treatment is absolutely not an appropriate punishment. In fact, it should almost certainly never happen at all, no matter what the circumstances.
There’s much more to be said about this, but I’ll save that for a later time.