I still see unbound pkgs in both locations for the 19.07 release:
However, I don't see any unbound pkgs for mips_24kc snapshots currently. I'm pretty sure they were available (though not necessarily from this location, because I didn't start searching until opkg suddenly tells me unbound is an unknown pkg). I'm certain the unbound-daemon and unbound-daemon-heavy pkgs have gone away in favor of a single heavy unbound-daemon pkg in earlier snapshots. Of course, it doesn't matter as there seems no unbound pkg at all, for snapshots:
engines/e_devcrypto.c:24:10: fatal error: crypto/cryptodev.h: No such file or directory
#include <crypto/cryptodev.h>
^~~~~~~~~~~~~~~~~~~~
compilation terminated.