Signal is probably the best replacement for WhatsApp because is verifiably End 2 End Encrypted.
So even if the Signal Foundation or Amazon where their servers are hosted decide it's time to do social graphs, at least the content of your messages is encrypted.
To escape metadata surveillance it gets more complicated, but it would probably involve a mix of TOR and XMPP or something.
GNU social JP is a social network, courtesy of GNU social JP管理人. It runs on GNU social, version 2.0.2-dev, available under the GNU Affero General Public License.
All GNU social JP content and data are available under the Creative Commons Attribution 3.0 license.