There are multiple apps that help shopify sites send whatsapp msgs to abandoned cart users. If the messages are send manually, stores can use their phone no. If automated, most apps use their numbers. This is the disclaimer one of the apps puts:
Note: Messages are sent from WhatsApp Approved Bot Number. Though we are sending your WhatsApp number direct (wa.me/<your whatsapp number>) link with all messages, Customer can contact you using that link.
From what I understand, sending msgs like these without customer's permission (what whatsapp calls opt-in) are not permissible under its privacy laws. Infact I know someone (not using Shopify, but a different business) who sent manual whatsapp msgs to leads gathered through their website and whatsapp blocked the number.
I understand that the business needs to have a whatsapp approved no and get the customer to opt-in before they can initiate a conversation with the customer on whatsapp.
Given all this, are these apps allowed to send msgs on mechant's behalf? Is it legal? Since they are endorsed by Shopify, can someone from Shopify apps team throw light on this?