I'm confused about what they would be suing for? Based on the example of Nintendo, if people were sharing links to download Switch games or something, yeah then you would have a copyright concern.
But Nintendo can't sue anyone for simply talking about Nintendo products. Forums have existed since the birth of the internet, and they'll exist long after whatever happens to Reddit, for example.
The horizontal blocks UI with post content on the left, and discussion on the right, frankly sucks. Weird font choices across the interface as well.
Scaling costs will be untenable if Squabbles ever starts to gain serious user traction, and then they're in the same predicament as Reddit - you have to monetize somehow in order to pay for the infrastructure. That's either ads, paid subscriptions, or selling your user data.
I don't see how this is any better than Reddit.