Specifically, I had changed my profile picture on WhatsApp to the Signal logo and my ‘About’ text to ‘Message me on Signal - https://signal.org/download/’. However, I noticed recently (after someone happened to open their WhatsApp in front of me and I saw their chat with me) that my WhatsApp contacts are seeing my profile picture and my ‘About’ text as blank. I've checked and this seems to be the case for all of my WhatsApp contacts.
See screenshots from me and my friend's phones here: https://imgur.com/a/qvEsswW
On the bright side, this serves as an ideal demo for convincing anyone who doesn't understand why I am trying to migrate them over to Signal. So, I guess, thanks Meta?