1 FB BM ID can be used for multiple WABA account, and 1 WABA may host 25 different phone numbers. There is no limit currently on how many WABAs can be created for a given FB BM ID. But each WABA should ideally represent a different business. Templates will not be shared across WABAs. Precisely what it mean was that ideally, 1 WABA should represent the business. If the business is large enough and has multiple business units, they can use the same BMID to create multiple WABA to suit their needs.
