There's no way to re-activate social connect with our app. Our app allows you to log in via social networks for the customers who created their accounts via our app only. It was developed this way because to log customers in automatically our app has to set a one-time password for their account. That's the only approach possible with Shopify. If we do that for the account that was created manually (with the email and password), customers will not be able to log in with their passwords anymore, so it will be very confusing.
In other words, you may just remove those accounts, and then customers will be able to log in again via our app. But you may lose some accounts if they don't log in again. Otherwise, they will get an error message that they already have accounts and should log in with their email and password.
