Definitely a possibility. However, it's worth mentioning that the pronunciation of bat'leth (ˈbætˌləθ) is so far from batlh 'etlh ('bɑt͡ɬ.ʔɛt͡ɬ) that writing it thusly would barely make sense. [My IPA transcriptions aren't necessarily perfect, but they should be close.]
However, Marc does retcon this in Klingon for the Galactic Traveler, where he states that betleH is an archaic form of batlh 'etlh (presumably dating back to the days of Kahless), but that the latter is rarely used except to explain the word's etymology. Similar to the way the word starboard should really means something like "steerside", but nobody ever says that.
Also, as people say, words like Fek'lhr can easily be explained by considering the fact that Kronos must have many languages, and that those have evolved over time. Heck, this is necessary to explain most of the Klingon dialogue in the various Star Trek series, which bear little resemblance to Okrand's tlhIngan Hol.
In romanized tlhIngan Hol, Fek'lhr's name is spelled veqlargh, and pronounced roughly as Worf pronounced it in Devil's Due. It could be that the spelling Fek'lhr makes sense when you consider the pronunciation in some other language (or an older form of the same language), just as the silent k in the English word knife makes perfect sense when you consider the word's etymology.
