I think he was rather excited about it because he loves rare orthographical patterns. (As do I)
Briar. That removal of hyphens is actually part of Englishes rules of word construction. Hyphens are used to create words which are not widely used but are craftable with two words. As they become more widely used, the hyphen is no longer needed for people to understand it as one word.
"La Petveturista Gvidlibro pri la Galaksio" seems to be a better translation (https://eo.wikipedia.org/wiki/La_Petveturista_Gvidlibro_pri_la_Galaksio). Ne paniku!