The phrase "much discussion" means that a topic or issue has been talked about a lot, with many people sharing their thoughts and opinions. Full definition
With so much discussion of bullying and an Internet rife with false information and misleading statistics, it can be difficult to keep the issue in perspective. (stopbullying.gov)
There wasn't as much discussion about whey elevating blood sugar. (flippingfifty.com)
She's decided, after much discussion, to take part in a kids art show / sale later this year. (soulemama.com)