I think not only BNB will be the competitor of eth since the nrw trend IEO open the era of exchange offering for some projects. All coins that has exchange affiliate will be the contender since they will use their own coin to make a market strategy and pump their own project.

But eth woulndt die for that. After purchasing the coin for the IEO, the people will sell those coins in return of btc and eth so I dont think the purpose is to kill eth or btc here.