I'm sure Kubrick didn't say anything about his interpretation of the ending. He wasn't in the business of interpreting his films for the audience. Kubrick didn't see that as part of his job and when controversy erupted over A Clockwork Orange a few years later he wouldn't have a thing to say about it in public, either.
Claiming that the writers had no idea what was happening, though, seems incorrect. Clarke certainly had his own ideas about the ending, which you can read in his 2001: A Space Odyssey novel. Of course, Clarke later stated publicly that he didn't know what to make of Kubrick's ending, either, IIRC.
Regardless, the ending conveys enough information for me. Namely, that Bowman transforms into the star child. The presence of the monolith at the beginning of the star gate sequence and the end of the film rather firmly suggest that it is the same alien intelligence doing this that manipulated early man and planted the monolith on the moon. What this exactly means, besides (probably) being the next stage in human evolution (manipulated by an alien hand), though, is left ambiguous. On that point I don't have any problem with the film. To the apes in The Dawn of Man sequence, we would be completely incomprehensible. And so is the star child to us.
Claiming that the writers had no idea what was happening, though, seems incorrect. Clarke certainly had his own ideas about the ending, which you can read in his 2001: A Space Odyssey novel. Of course, Clarke later stated publicly that he didn't know what to make of Kubrick's ending, either, IIRC.
Regardless, the ending conveys enough information for me. Namely, that Bowman transforms into the star child. The presence of the monolith at the beginning of the star gate sequence and the end of the film rather firmly suggest that it is the same alien intelligence doing this that manipulated early man and planted the monolith on the moon. What this exactly means, besides (probably) being the next stage in human evolution (manipulated by an alien hand), though, is left ambiguous. On that point I don't have any problem with the film. To the apes in The Dawn of Man sequence, we would be completely incomprehensible. And so is the star child to us.