In this context, I think they meant "free speech" and "objectionable material" referring to the same things, but by different groups. So death threats would fall under both: Gab would allow them, most other Mastodon communities wouldn't. People (or law enforcement agencies) can then choose their gatekeeper.
Gab, per their claims anyway, use US law as their guideline (plus banning porn). I know they've removed at least a couple people who cross a certain line when it came to directly advocating violence.
