Automatic birthday messages on WhatsApp
WhatsApp can remind you of a birthday one day. It still will not send the wish for you. Bday Message links your WhatsApp and sends the text you wrote, from your number, on the morning of.
WhatsApp does not send the wish for you
There is no official switch in WhatsApp that fires a birthday message from a personal chat. Reminders, if they arrive, still ask you to open the thread and type.
Bday Message is for people who want the message to leave without that last step. You write it when you have time. It sends on the date you saved.
It sends from your account
You scan a QR code and link WhatsApp as a companion device. The recipient sees your name, not a business profile and not a bot.
That is the point. A template from an unknown number does not sound like you.
What WhatsApp will not give you
WhatsApp does not share contact birthdays. You type the date, import a file, or pull it from Telegram if the same person is there.
A linked device can be dropped. We say that on the connect screen and in the terms. If the session dies, we email you so you can link it again before the next birthday.