They're free to download, but IIRC you're still abiding by their EULA. Apple are threatening to revoke Epic's EULA license. If that happens, Epic would be using

They're free to download, but IIRC you're still abiding by their EULA. Apple are threatening to revoke Epic's EULA license. If that happens, Epic would be using the SDK "illegally". (This is all speculation, IANAL, feel free to correct me if you have a better legal understanding of this)