It doesn't talk about whether the 22% includes messaging apps too. The line between social media and messaging is pretty blurred. Someone might stop using fb but join a WhatsApp group
I do agree that 'social media' has been used to describe large scale public social media platforms specifically by the reporters/media.
Telegram is much better since people dont see your phone number if you don't want (I dont use telegram for its optional encryption feature), the group chats can be way larger and the source of forwarded messages can be seen and accessed