Yup that's basically it. The hack was just in getting Tensorflow to accept/load its neural network definition from the JS bundle (what CodePush distributes for you) rather than from the main Cocoa bundle.
See https://news.ycombinator.com/item?id=13817557 for some more detail/discussion.
[edit: Apart from in Apple-approved manners]
> 3.3.2 […] The only exception to the foregoing is scripts and code downloaded and run by Apple’s built-in WebKit framework or JavascriptCore […]
If the newspaper apps get to load fresh front page images, why should a poor neural net be discriminated in its quest for fresh coefficients?
(Raw oppression and injustice there, get yer indignation reservoir topped up.)