Additions and changes to the Twilio platform
Businesses can now move their existing WhatsApp Business API phone numbers to the Twilio platform at any time whether they were previously registered through a different Business Solution Provider or directly with Facebook. Upon a successful migration, the transferred number retains its display name, messaging limit tier, quality rating, and Official Business Account status. High quality message templates on the account that it was previously registered on will also be copied over to the new account on Twilio.
For more details on how to move WhatsApp numbers to Twilio, please take a look at this support article.