You wouldn’t be able to MITM a plaintext connection inside a corporate network with this attack by itself. You could only MITM something that the attacker can access without your VPN.
Any corporate network that has an unsecure, publicly accessible endpoint that prompts for credentials is begging to be hacked with or without this attack.
Now you could spoof an login screen with this attack if you had detailed info on the corporate network you’re targeting. But it would need to be a login page that doesn’t use HTTPS (any corporations, dumb enough to do that this day and age are begging to be hacked), or you’d need the user to ignore the browser warning about it not being secure, which that is possible.