“I believe that Free Republic is self-hosted, and isn’t relying on a big hosting service like Google, Microsoft or GoDaddy.”
I don’t know where people get this from. Free republic has a host that they pay a fee to use. The same thing can happen here as happened to Gab and 8chan.
8 Chan went off line when Cloudflare stopped providing their DDOS protection service. I don't believe that FR uses that service.
Gab went down when GoDaddy dropped them. I believe GoDaddy was both their Domain Name registrar and their hosting service. Like I said before it's probably best to have two separate companies providing those services if you are publishing controversial content.
Maybe I'm naive, but I don't see FR as particularly controversial. 90% of posts are linked from mainstream publications, and people comment on them. The mods quickly remove anything that violates the terms of service.
The comments on local newspapers that still allow them are much worse than what you will see here.
I'm not sure I got the idea FR was self hosted, perhaps it was from back in the old days, when we would have an outage the resolution usually involved the mods getting hands on with hardware and software, which doesn't happen if you are running on GoDaddy.