Just wondering, is it already possibly to migrate questions from other stackexchange sites such as stackoverflow to Reverse Engineering?
Same for questions like this question that have already been closed.
While it's technically possible to migrate questions, the migration paths are not set up until a site becomes well-established.
But beyond that technical limitation, building this community from the old, pre-answered questions of another site would do this site a terrible disservice. That's not how you want to build this site.
Forget for a moment that other site may not want their content removed like that (along with the the knowledge and reputation earned). Consider that, from day one, your brand new site will be filled with old, pre-answered anonymous questions, as the original authors are off on another site.
The creation of this site was a somewhat controversial. The subject is already covered to some extent on other sites. But the idea of creating a site dedicated to Digital Preservation is to build a community was supposedly not being well-served by another site. I wouldn't rush to simply migrate someone else's content content here. Continue focusing on building your own community. You should focus on building your own content with properly curated solutions, built with the community and expertise that genuinely belongs here.
That was the point of creating this site in the first place.