" Is there any way that someone views the codes through using .exe files?"
Mathworks could do this. The reports I have seen are that they refuse to do this even for money, but there is little doubt that they could if they wanted.
I have seen one unsubstantiated claim posted that a particular person (not associated with Mathworks) can do this.
Based upon what I know of the technology involved, it seems plausible to me that someone could develop programs to decode the executables. Most of the time,though, it is not worth the bother.
Mathworks makes it clear that you should not count on their protections to make it impossible for anyone to read your code.
Let me put it this way: you might have gone as far as purchasing a hardened lock for the front door of your residence, that might slow down anyone trying to get in, but there are very few doorlocks that cannot be picked given enough time. (Some of the doorlocks with seemingly strong protections turn out to be quite easy to get through if you have just the right equipment on hand. Experienced lock-breakers count a lock as being "difficult" if it takes them more than 30 seconds to open with the right tools.)