Players serious about developing their game eventually become obsessed with "Jedi mind tricks", bluffs, and representation on both their side of the table and their opponent's. What I want to address is the minor fact that for every Mike Long combo-ing off without a win condition, or Zach Hall foiling Mike Flores' dastardly plans with a well-timed "#showme", there are hundreds of thousands of examples of completely ineffective angle shots.
Being able to rationally determine the likelihood of a specific card in your opponent's hand is a valuable tool. But I prefer the golf bag analogy. When it comes to our game, you have many different skills and abilities that you need to develop. Understanding card advantage, proper role identification, card evaluation, and careful attention are all clubs in your golf bag. The point of the game of golf, though, is not to use every club on every hole. You want to get there in as few strokes as possible, which isn't going to happen if you spend time trying to convince yourself a flop shot over a towering pine tree with your new lob wedge is the right play.
In Magic, you will encounter many situations where your opponent could ostensibly have something in their hand which will affect your board position or plays. In fact, those situations come about literally every turn.
I used to enormously enjoy the old Magic Academy and The Play's the Thing series and other articles that focused on the same sorts of things. When someone whose opinion I respect very highly is explaining that playing a Razorverge Thicket instead of a Forest before casting Llanowar Elves is just like taking a baby cat outside and kicking it against an electric fence because you want them to believe you do not have access to white, I try very hard to pay attention, but, ultimately, not every play on every turn is as crucial as you want to believe it is.
To summarize my occasionally incoherent thoughts on this subject, I'll say that I very rarely play around Rebuke in DII drafts. If my opponent has it, it isn't going any where. Whether I attack this turn or six turns from now, I'm going to lose a guy to it. If it's early in the game, I can be fairly certain that whatever I'm attacking with is going to be worth less than the better cards I'll have access to later.
In conclusion, the pro tip of the day that I'm referring to is "In the early game, play as though they don't have it, and in the late game, play as though they do." I'm merely adding that in most actual situations, it doesn't matter either way.