Is it really relevant here? If not, should we start marking them to be closed?
For managing and maintaining your own hosted web application please ask on Pro Webmasters
DHIS 2 appears to be a self-hosted web application. It also offers data management and analytics, along with visualizations and charting, so might have been assumed to be a webmaster's application like Google Analytics. That's likely why they're migrating these questions to us.
On our site, the section on What topics can I ask about here? states in regards to web applications:
Web sites out of your control -- If the question is about another site (such as Gmail or Facebook) and not about your own website, it is off-topic here. Web Applications would be a better place to ask.
Since DHIS 2 is self-hosted, these questions are likely about websites under the OP's control.
In some cases with web-based applications, as with MediaWiki for example too, there doesn't seem to be a perfect Stack Exchange site to fit them. Given that they're non-commercial and could be used by webmasters, I'm inclined to let them live on so that their OP's might receive an answer, as it appears most here have.
If we closed them, that amounts to rejecting the migration from Web Applications so the question would remain on-hold and unanswerable there, and then get deleted after 30 days -- essentially dead-ending the question.
As I see it, another satisfied OP or visitor here might come back for more generally applicable webmaster questions and answering, which is beneficial for the site in the long run.
In short, if the question is related to a self-hosted web application used for the OP's website, and doesn't appear to be outside our guidelines otherwise (e.g., is an advertisement in disguise of a question, is coding-based, etc...), we shouldn't close them.