Earlier quoted context omitted.
To be fair, though, 2001: A Space Odyssey didn't explore nearly as many exotic phenomena as Interstellar did. It was a lot easier for that movie to remain mostly accurate.
2001 explored some pretty darn exotic phenomena, it just didn't both to try to explain them scientifically.
Did you have some specific examples in mind? I still feel as though 2001, excluding its ending, stayed much further away from speculative topics of theoretical physics than did Interstellar (which in fact has explicit references, in its dialogue, to "the bulk" -- a term from brane cosmology; see http://en.wikipedia.org/wiki/Brane_cosmology).