WordPress questions were never declared as _off topic_ on Stack Overflow, and there are some [rules](http://blog.stackoverflow.com/2012/03/respect-the-community-your-own-and-others/) preventing migration:

* Low quality questions are closed, not migrated.
* If something could be _on topic_ on two sites, the questions stays where it was asked.
* The tag `wordpress` on SO isn't always used properly. Many of those questions would be off topic here (I'm following the tag).

We get already more questions than we can handle. People who prepare their questions properly will find our site anyway. Those who don't will ask on Stack Overflow. We don't need more _bad_ questions.

In short: I see no harm. We should focus on _our_ profile and care about off topic questions here more than on SO.