BOLT 12 is an upgrade that aims to enhance user experience and privacy. It introduces features such as re-usable payment requests, increased receiver privacy, and better censorship resistance. BOLT 12 allows for more flexible and extensible ways to structure and exchange data, making it easier to add new features and improvements without disrupting existing implementations

What do you mean by "flexible and extensible ways to structure and exchange data"? Can I send a text message with my payment now, or no?