That does not seem like particularly notable example of foresight & robustness, given that it’s such a low number of maximum tasks, and such a fundamental & frequently used element of its operation.
Like it wouldn’t even be describable as a “rescue itself” if the response was simply “No. Too many jobs running. Please kill one to continue”
It is infinitely harder to be first. Once it is known that viable path exists, the task becomes a lot easier
You’re forgetting this had never been done before.
The Apollo Guidance Computer had 4KB of RAM and 16KB of ROM. Can you write a scheduler that would execute 8 programs related to landing on the moon in 4KB?
At that time running that many concurrent tasks on such anemic hardware was a small miracle. This wasn't your average linux kernel.