I think it's entirely possible that "creativity" is the introduction of entropy into biological systems. Whether that's through the environment (perspective) or genetics. I'm not sure that AI is bad at purely abstract things as its roots lay in the abstract. It is however pretty bad at interacting with the physical world (besides a few very focused and specific tasks).

Ultimately though you need to dive in the Turing test. When we can't tell if AI is sentient or not, it should be considered sentient. Would a robot "brain" (intelligence) be sufficient to provide evidence for "proof of brain", or are we purely interested in the human brain?