There are directives for telling whether an article is a Disambiguation page. I would like to know if there is any directive/Wikimedia Template used to flag an article as a list?
So far the only way I've found to check this is via Wikidata's P360 Property, but Ideally I would like to get this information from the Wikipedia XML dump.
There isn't such information in the article, but you can check the title if it start with "List of...".
I'm not sure that all items which have Property:P360 are list articles (for example some disambiguation items like Q3086), but you can access them by MediaWiki API:
https://www.wikidata.org/w/api.php?action=query&list=backlinks&bltitle=Property:P360&blnamespace=0&bllimit=500
All list articles are marked in Wikidata by instance of Wikimedia list article (Q13406463). You can get all them by using WikidataQuery API:
http://wdq.wmflabs.org/api?q=claim[31:13406463]
Currently they are 216,685 (104,843 in enwiki)
You can also filter all items with P360 which are not disambiguation items:
http://wdq.wmflabs.org/api?q=claim[360] AND noclaim[31:4167410]