I am so glad @SextusEmpiricus asked this question, and I have been visiting both sites before this quastionquestion was posted. That said:
Top Answers' Code of Conduct is "Be nice." which seems ripe for abuse, and ripe for implicit biases to manifest.
If Codidact has a Code of Conduct, it is not immediately visible.
For all SO/SE's execrably poor decision making over the past five months, they are actually making an attempt to implement an inclusive environment via a Code of Conduct. I won't be participating in either alternative site without similar work foregrounded to all visitors.