My point is, there is already an app for that. Signal has a completely different purpose.
As for the DNS, if you're concerned with the DNS of your ISP, you shouldn't be using it anyway (I don't).
Don't extrapolate what I said. I like link previews and don't like Memojis and bloatware. But more often than not I like to know what's behind the URL. Maybe I don't wan't to open the site, or already seen the article, or the preview is enough to get information (like weather?).
If we're on the road to proliferate privacy-conscious behaviour, we need to give something to "the masses", so they can enjoy the experience. And I want my mom and dad using products such as Signal, so I can use it with them. I have no use of it if my friends are not using it, and I'm all alone on the whole network. I don't support bloatware, but some sugar is needed.
https://github.com/signalapp/Signal-Android/blob/0ef01cc620c...
If you opened a PR with the websites you're missing, I'm sure they'd be open to it.
I see sibling comments mentioning that they wouldn't want this feature (which is already there) because of its privacy implications, but I think that it basically works like gifs, with a proxy controlled by Signal.