I'll put it this way, there have been dozens of reddit alternatives over the years. Of those, pretty much every single one that advertised free speech has gone under from right-wingers, psuedo-nazi's etc.

The fact is, the biggest subset of people deplatformed off of reddit or any platform are truly just awful^1^ , regardless of what they claim about unfair moderation. And if you don't make it expressedly clear that you will not tolerate them, they will flock to your platform. Any claims of "free speech" even backed by "oh but nothing too awful please" is basically a dog whistle to them and they will flock to your platform.

If someone says something like this, they're either naïve about how this works or they're just saying it to maintain appearances. Either way, the platform is doomed.

[1] well maybe not recently due to api issues, but they're still a huge subset and will be the majority again eventually