Not an important feature. But to get the webpage details such as image and a short description for any links sent from certain websites. This is only needed for popular websites such as YouTube, Twitter, Facebook, maybe news articles. This is a feature in WhatsApp and Signal.
And such a feature should have the option to be turned off.
It is already the case for the desktop client see and the android client is implementing it:
Hi!
Just wanted to start a new topic about this feature, but found this one.
Does anyone know how to disable this feature? I consider it dangerous (it actually make a request for any received URL) and privacy-threating (every time I open a chat, there is a unique-identifiable burst of network requests).
It was suggested that this feature must be dectivable. I can’t find the knob to turn it off neither on Android, nor on desktop. 
Using the desktop client:
You need to go to Settings > General > Chat > Show link previews and disable that option.
I would like it if the preview feature was selectable per conversation.