Are the 76ers placing Okafor and Noel on the trading block because of what they've seen in Embiid or is it because they have more value relative to Embiid?
We can assume that if they're willing to part with their 2 best players without seeing Embiid play in an NBA game it is because he has thoroughly demonstrated his ability in practices and scrimmages. You don't give up Noel and Okafor unless you're sure that, barring injury, Embiid is better than the others. Coming out of Kansas, Embiid looked great on both sides of the ball very much like Towns. Be will be 2 years older and stronger since then, the 76ers are rolling the dice that he's better than both even while not being as valuable as them at the moment.
If his medical records are clear, you make the trade.