Interesting. I wonder, were these rules well known among players/press at the time or was the industry still young enough that people didn't pay attention to the business details? (I was young enough to not pay attention, anyway! ^_-)
Some of the industry trade publications (which in the late 80s really just consisted of EGM and little else) did report on things like that sparsely. Tengen made a lot of noise at the time where, rather than abide by Nintendo's licensing restrictions they started publishing unlicensed games (after having published three licensed titles), Color Dreams was next (they were a licensed Nintendo publisher, but decided to follow Tengens lead and make unlicensed carts, rather than deal with Nintendo's high minimum order requirements, slow turnaround time, content restrictions and other regulations by the late 1980s), then other publishers started to pop up publishing unlicensed carts rather than deal with Nintendo's rules.
A few of the early publishers, Tecmo, SNK, Activision, Bandai had different licensing deals with Nintendo that allowed them to do things like manufacture cartridge components themselves (Nintendo produced almost all third party cartridges themselves and took a healthy chunk of profit in doing so and by 1989 had very high minimum order requirements) among other things. This also led to a lot of NES games using different mappers than their famicom counterparts, one exception was Koei who produced their own custom mappers for some US NES carts. Other situations like Castlevania III led to substitute mappers produced by Nintendo being used, and as a result inferior ports of games from the Famicom originals.
Anyway, I've gone off on a long tangent. But yeah, Nintendo had a lot of third party restrictions in the NES heyday.