If you don’t get an initial status after 15 business days, it might be worth checking in with developer support to check if you can help clarify anything. With the recent news of large companies that should have known better being publicly caught using enterprise certificates to surveil non-employees and minors, I would only expect the requirements to qualify for enterprise accounts to get more legalistic and involve more paperwork. Also, there’s not much reason to go enterprise anymore so make sure you even need that capabilities before you undertake the vetting process.
On the good news, I’ve been seeing Apple just decline enterprise accounts and tell people to get a normal account. If Apple hasn’t offered that, I would reach out to the sales channel that took your money and/or developer relations (if you have a personal account) to check if you can submit any information to speed their review.
If they see you as a legitimate business and you have submitted more than a handful of apps through TestFlight then it will be far easier to make the case you are an enterprise. I would expect Apple to make a formal change to say that a requirement for an enterprise account would be to have three individual accounts submit apps to show that you’ve outgrown the normal developer path. You don’t have to release anything on the app stores publicly to show you’re an enterprise and submitting honest builds - everything can be internal testing.
I would expect that the number of enterprise companies that don’t have an account at this point is so low, the majority of applications are not truly enterprise 10 years in to this process.
My answer to the second question above has one public report of this shifting enterprise apps to normal accounts going forward. Time will tell if my hunch is right or if you just need your legal and business departments within the enterprise to contact Apple to show you have several developers and need of enterprise capabilities.