No, an admin may instantly block you permanently, or may temporarily block you until you change your name, or may temporarily block you while they discuss it with you, or may not block you but apply one of two templates, or add your name to a username for discussion board where you'll have to try to justify your name.
EDIT: Reads some stuff about his company. He knows that information is factually incorrect. It's not harmful to his company, but it is misleading to people reading Wikipedia. He signs up for an account.
If he signs up a "xargleblarg" he's fine, he can edit the article.
If he choses to be open and honest and he signs up as "Bob from BobCo" he faces instant blocks across multiple policies (COI, Spam, spam username), even if those policies are being incorrectly applied.
The only interactions I had with Wikipedia are reading articles. Even I know it is frowned upon to edit your own articles.