Yes, I'm very familiar with the Pierre Boulle novel, and while I thought it would have been fine to have gone back to the source material, I didn't think the Burton versio was anywhere near truer to the book, and I'm not sure where you're getting that.
The novel had a more advanced civilization with motorized transportation and everything. It also contained baboons, as well as the other three society sects depicted in both versions. The novel had nothing to do with "accidentally" starting a race of intelligent apes. There was a double twist in the novel, but this wasn't one of them. Some of the ape names carried over from the novel to the first adaptation. To my recollection, none carried over in the Burton version. Aggressive chimps? C'mon, that wasn't in the book. Would love to know what you specifically thought WAS closer to the novel.
Bottom line, we're in age of inevitable remakes and re-envisionings. The novel is far more obscure than the 1968 film, so I'm really doubting anyone would have had the imagination to go back to a 1960's novel for something fresh. No, it had everything to do with the cash-in-ability of the Apes films already done. Damn, they couldn't even come up with a new logo, that's how much they were counting on ties to the '68 movie.
I don't even see the Burton movie as even a new adaptation of the novel as a re-envisioning of a past adaptation.