So? He still either (A) telegraphed his intention (in which case, he is "stupid" by his own logic), or (B) did not telegraph his intention (because he didn't really mean it).
Liars and stupid people often keep others guessing.
So is Trump "keeping 'em guessing" because he is stupid, or because he is a liar?
Personally, I think it's because he is a liar and is no different from any other self-serving political hack who tells people what he thinks they want to hear:
So you basically you are telling us that Trump was lying when he told the NYT yesterday that he isn't going to prosecute Clinton and it's actually some super secret strategy to actually prosecute Clinton? The orange one can do no wrong can he?