[zulln]

Signal is registered as a 501c3 nonprofit, there should be challenges to buy that. Granted, I have not investigated if someone else holds a trademark or so that maybe still allows for something to be sold.

Signal not only encrypts messages (Whatsapp does as well), but also seem to make sure there is as little meta data available as possible. This should make it less interesting for eg. Facebook to buy them.

[antibuddy]

I do not know about their attempts at minimizing meta-data however I guess the usual meta-data like who texted whom and when is still there. Maybe it is not stored, but I have to take their word for it (and I tend to believe them), but the data is still there.

This data is there at any rate however confederated chat apps can use different servers (so data is not congregated) and you can also change accounts easily (it's harder to change phone number).

[zulln]

I have not looked into how it works, other then reading the blog post, but it seems like they are trying to figure out that part as well: https://signal.org/blog/sealed-sender/

But yeah, as long as they own the servers I am sure they could puzzle it together if they wanted.

[grlass]

worth looking that the cwtch.im alpha chat app, that attempts to mitigate the metadata problem with TOR, and having untrusted servers that host group chats.

Similar philosophy to Signal of trying to really get usability right (looking at you, Element). Though still early in alpha development, wouldn't trust current alpha builds to be reliable.