I think non of the top altcoins will die off like that. But some half dead projects may die. There are handful of projects like that (Das looks like one)
Yes, if we look at the very top on marketcap nowadays, eth, ripple, litecoin, dash, monero, zcash, neo are not likely to die. I am not sure about these other coins like iota or nem, though. But they don't mean much even nowadays. Just look at historical snapshots and you will be convinced. In august 2016 top coins where eth, ripple, ltc, steem, etc, dash, nem, maid, nxt. Now among these only nxt, maid and steem are not top 10 but they're still in top 50.