This sounds like what Element has been doing for years already. You can sign up with an email and optionally link a phone number to your account. When WhatsApp does it though, it's newsworthy.
In the realm of "business WhatsApp Web," this advancement could signal a heightened focus on providing secure and reliable communication tools for enterprises. Businesses often leverage WhatsApp Web for efficient communication, and the introduction of email verification could be a proactive measure to address the unique security needs of corporate users.