There is no penalty for duplicate content (if you take that content from another site you posted on yours). Google went on record several time on this subject. But you won't rank with this content anyway.
Now if your site is 10-100 pages and you get 15k in - then you will change the topicality of the site by a lot with thin content that doesn't rank and dilute everything you have and that is not good. If your site is 200k pages indexed already and you add 15k - I would't really worry about it.
To play it "safe" you could indeed noindex them. Those will still be crawled if they are linked though. If you want to cut them out and also save some crawl budget (if the site is new and with not that many pages) I would push all of those 15k pages in a separate folder in the structure and add that folder in robots.txt as disallow.
Take into account that linking to those pages and having those pages indexed is also a signal for the pages that are linking to them (good or bad). If those are on the same topic it will help the pages that are linking to them.
If you can find the time and energy to improve this content even if it's the same like on any other sites, find a way to add some value (in the way you show it, with resources, stats, addon con tent etc) those can turn into a good set of landing pages.
my 2c. Hope it helps.