I'm sorry to say I don't know. But I can tell you what I suspect, and I suspect that they are probably not reviewed. My understanding is that the entire ministry responsible for immigration is under-staffed. I'm not sure they have the manpower to do this, even if they want to.
But the other thing is that these profiles expire after 1 year. So I'm not sure what possible good reviewing expired profiles would do for anyone, unless IRCC had reason to suspect fraud.
Finally, one last thing to try to reassure you: I don't know to what extent the creation of an Express Entry profile could be considered actually filing an application. When you respond to the ITA, you are definitely submitting an application to IRCC. But I can imagine someone arguing convincingly that an EE profile that was never going to get an ITA in the first place is not an immigration application.
All this being said, you should remember that I am only the webmaster, I am not a lawyer or an RCIC, so everything I say you should take with a big grain of salt. This is just my opinion.