Most showstoppers come from the fact that the Saturn/Apollo programs are not active, and have not been for a long time.
Human rating primarily applies to the design process. The Saturn/Apollo were not under these requirements, and is thus not designed in a fashion compatible with it.
There are no longer any people that are responsible for the various components. Compliance requires the existence of people that are maintaining their part of the system. A part can't be compliant by itself.
I will argue that this is what ultimately makes compliance impossible. The program just doesn't exist. What exists is various debris, archives, museum objects, and people's memories. Human rating applies to "space systems" as defined already in the preface, and the Saturn/Apollo programs are not space system.
"But would it have been compliant back in the day?"
A space system is the paperwork just as much as the hardware. For the paperwork part, the anwer is a clear "no", as this paperwork fundamentally can't exist as the standard is newer.
The rest of this answer will be about the hardware, wheter it could theoretically meet the standards or not. I maintain that the above is the real answer, but some will not be content with that. That a certain component meets the standard can only be speculation as there's no paperwork that says it does.
22.214.171.124.1 The space system shall provide the capability for the crew to initiate the Earth ascent abort sequence. Note: The ability to inhibit an automated abort initiation is described in paragraph 3.3.2.
Apollo had abort modes that could be initiated manually and automatically.
3.6.6 Lunar Ascent Systems Reserved for a future version of the NPR.
The Apollo lunar lander is here operating outside of the standard since there's no standard yet.
3.6.5 Lunar Surface Systems
The space system shall provide the capability for the crew on the lunar surface to monitor the descent and landing trajectory of an uncrewed spacecraft and send commands necessary to prevent a catastrophic event.
The lunar lander had an abort mode covering this
126.96.36.199 The crewed space system shall maintain a safe and habitable environment for the crew inside the spacecraft after Earth landing until the arrival of the landing recovery team or rescue forces.
The crew could stay in the Apollo capsule for some time after splashdown.
188.8.131.52 The space system shall provide recovery forces with the location of the spacecraft after return to Earth.
There were numerous ships and aircraft doing this.
3.6.2 Earth Orbit Systems The crewed space system shall provide the capability to autonomously abort the mission from Earth orbit by targeting and performing a deorbit to a safe landing on Earth.
Note: Where possible, the crewed space system should provide a backup capability for entry to protect for loss of the primary attitude control and guidance system. Paragraph 184.108.40.206 addresses scenarios where this may not be applicable.
To my knowledge, the Apollo module could not realistically be controlled by the crew without the primary attitude control (RCS)
3.2.12 The space system shall provide the capability for the crew to readily access equipment involved in the response to emergency situations and the capability to gain access to equipment needed for follow-up and recovery operations.
Note: Fire extinguishers are one example of the type of equipment needed for immediate response to a fire emergency. "Ready access" means that the crew is able to access the equipment in the time required without the use of tools. The ready access time will depend on the phase of flight and the time to effect of the hazard. Ready access also accounts for suited crew members if the equipment could be needed during a mission phase or operation where the crew is suited. A contamination clean-up kit is an example of equipment needed for follow up and recovery operations.
Many statements are intentionally general like this, but the note does mention fire extinguishers. Apollo had those.