Most likely we will see some new ICOs in the future that will have an even more advanced tech and even more hype around it, so I'd say it's gonna be a different one.
Possibly but becoming established as the first security token platforms will carry these projects a long way. Its the same reason that Ethereum will remain relevant for a long time, even if better tech comes out.Of course if Ethereum and in turn the current security token platform projects can continue to evolve, they have a huge advantage over younger projects just stepping into the game.