I dont think one specific discord would have a major impact, but discords in general I would bet have an impact on some games. One game at a regular payout level doesn't correlate to discords not having an impact.
I'm pretty positive it has a much larger effect on other trivia apps though. Like with Cash Show you could see a huge difference in pay every night if the discord happened to get a major question wrong, but otherwise the amount of people to stay in the game in the later questions was pretty much pinned to around 2,000 people every single night. When there is a huge dropoff on players going out after a certain question, it's pretty obvious they are pooling their resources.
HQ is just a lot bigger and does a better job at making a few google-proof questions, so the variance on payouts is better which would make it hard to notice if there was a disruption.
Also there were other discords that saw a huge flood of players tonight.