Hoi,
You have it backwards, in my opinion at least. When someone is notable enough for a Wikipedia article, create a Wikidata item and include all the pertinent information for that person. You may even be surprised in finding that the person already exists. There are many people from the USA or the UK who have an article in a Wikipedia but not in the English Wikipedia.
When the known information has been entered, you will find in the Reasonator a text generated based on the available information when the subject is a human. This is proof of concept functionality that is best developed at this time for English.
What you are proposing however is something else; have Wikidata information included based on an article. There are several parts to this; when a subject is part of a specific category or lists, it would follow that specific statements can be made based on this information. When an article has a specific template / infobox the information in the infobox implies specific statements. This is a bit of an issue; when Wikidata already knows about a subject and has that information it could serve the Wikipedia with that information. Who says that new information from a Wikipedia is better than existing information in Wikidata ?
So yes, there is room for activity on available information in a hackathon. However, the notion that Wikipedia has the information first is a false premise; Wikidata has more than 50% more items than en,wp has articles.
Thanks,