Hi Joel,
I think you may be searching incorrectly. When I search "site:http://geohub.brampton.ca parks" I get many results including pages, datasets and apps. I think you may be mislead by the portion of the url that includes `/datasets`. All types of content load under `/datasets`. We're working on improving those url fragment so they more closely represent the content type that is being loaded, but we do not have a timeline to share for that yet.
We build a lot of features into our sites to make sure google can index well including sitemaps and metatags. We also conduct testing to ensure googlebot can load our pages and pay attention to load time affects page ranking.
I recommend setting up Google Webmasters tools so you can get more direct insights into how Google is crawling your page and any errors that may be occurring.
I hope this answers your question. Please let me know if my explanation does not make sense or fully answer your question.
Daniel Fenton
Software Engineer | ArcGIS Hub