[bonoboTP]

In machine learning / computer vision people often release their code after the paper is already accepted.

Time before the submission deadline is usually used to do more experiments and write text, not to polish the code. And after the deadline there is no hurry. What people (who want to share code) consider important is to release it till a bit before the actual conference (but this doesn't transfer to journal-based fields).

[kolpa]

The paper should be accepted in rough form, but publication should be held up pending approval of the data and code.

Or a paper should be published in a probationary form, and not certified (by the journal) until an independent lab replicates the result. A paper that isn't making adequate progress toward replication should be retracted by the publishing journal.