Maybe they are, but not necessarily. I think that some of the function words may not be commonly used in Penang because they weren't commonly used in ordinary people's speech in China either, and were transmitted into Hokkien when ordinary people had more contact with written styles of Chinese. Written styles use long sentences and need to be precise, whereas much of the spoken language can rely on situation and context.But these are of course just paraphrasing strategies, to cope with limited vocabulary.
I have a nice passage somewhere about the use of these words (and their absence) in a book called "Cantonese for Malayan Students" published around the same time as Bodman's Spoken Amoy Hokkien. I'll go off and find the direct quote.
I have noticed I've been writing cho (give) wrong for weeks now (as chO or cho'). I think I'll stop now...