Does SPO support Whatsapp, iMessage, Pinterest link preview or other social platforms?
Yes, but there is a catch.
Basically, Whatsapp and iMessage are using the same social meta tags as Facebook. However, they may have conflict in the link preview image size. Facebook & iMessage prefer to have an image ratio of 1.9:1 width-to-height ratio while Whatsapp requires 1:1, i.e square.
We don't support Pinterest at the moment. Please raise a feature request to let us know your need.
Additional Reference:
Best Practices for Link Previews in Messages for iMessage - https://developer.apple.com/library/archive/technotes/tn2444/_index.html
Provide an image for WhatsApp link sharing - https://stackoverflow.com/a/43154489/7118663