Why is it mandatory for users to give an email if sms is set as preferred communication method?

Summary:

Steps : Actions > Send Message

In our case, the candidate has selected sms to be their preferred communication method, but when business users are trying to send a message using the above navigation as they want to send a tokenized sms, they are being mandated to enter an email as well.

Content (please ensure you mask any confidential information):

I understand the Send Message functionality is normally used to send bulk emails to multiple candidates but need clarity on this specific case.

Version (include the version you are using, if applicable):

24C