No one said, nor implied, nor hinted, nor alluded, nor... that the government creates rights.
The government, by its very nature, restricts rights. It restricts activities that one could do absent government in order to protect the rights that really matter, the fundamental rights: to speak your mind, to espouse a philosophy or a religion, to associate with whom you choose to associate, to own, use, and trade property, to protect yourself, etc.
In addition to fundamental rights, which government cannot morally restrict, there are other rights, not fundamental (some being implementations of fundamental rights), that, as part of the creation of that government, were put off-limits to governmental intrusion. The RKBA, as it is specifically implemented here, is such a right: not fundamental, but an implementation of a fundamental right, one that was put off-limits to governmental intrusion.
No promise was made with the adoption of the 2A that possession of crew-served weapons would be protected. No promise was made in the BoR that the right to keep and use bombs would be protected. Nothing said that these activities would be outlawed, just that there was no promise of protection. They can be restricted, regulated, or outlawed.
The context and the history of the 2A makes it abundantly clear what the government was restricted from infringing: the right to possess and to carry personal arms (that could be carried), that typically had civilian use, but also could be used, in a pinch, as one's personal military weapon.