Yes, there was a mistake in the SELinux policy, which allowed the unconfined user to bypass the mmap_min_addr check, which otherwise would have been enforced if the check was enabled (many disable it to get wine etc. working, btw, google "disable mmap_min_addr"). This is being fixed in the policy.
The lesson learned here is that more careful review of policy changes needs to happen, and to ask the question as to whether the policy is capable of weakening default security.
The LSM interface is theoretically designed to only allow further restriction of access, but this is a special case, where we are applying policy to a kernel compilation option which can also have its value set via a sysctl. It's not a typical "access this resource or not?" decision.