LogFAQs > #910766564

The problem there is that most of the English NES and SNES manuals were written by people who had barely played the game in question, and had absolutely no insight into the intentions of the actual developers, so they'd often contain ideas and things which were more or less completely made up just to fill space. There's a lot of stuff in English manuals from that era that are absolute bullshit.

So it's possible that actually WAS the original intention... or it's possible that some intern in Nintendo of America noticed the ship and remembered there were ships in SMB3 and just drew a connection that was never originally intended.