[cameldrv]

Even whether an aircraft should be issued a type certificate is a judgment call. The regulations are not perfectly precise, and there is always going going be a certain amount of back and forth on interpretation and waivers and alternate means of compliance etc.

Even given that a type certificate has been issued, whether or not it is legal to fly depends on the circumstances of the flight. Just as an example, under part 91 (private flying), complying with manufacturer's service bulletins is optional, but under part 135 (charter) or part 121 (airline), it's generally mandatory.

Therefore, is the FAA saying it's safe to fly a plane that doesn't hasn't completed its manufacturer service bulletins? No. They're saying the acceptable level of risk under part 91 is higher.