If I were a social media mogul, my strategy would be to relaunch the same platform under a different name every 5 to 10 years. Put some new css in there, release some flashy ads, and users will think it's a different thing. Most IG and Whatsapp users are shocked when you tell them those apps are owned by the same company as FB.
On the other hand, there are some platforms so solid that they seem to transcend fashion. I'm thinking YouTube.