While yes Rumble is a centralised platform I really respect their policy towards copyright and that alone will likely chase away a lot of the copyright trolls that have completely infested youtube and drastically reduce false flagging which is one of the reasons the site is being wrecked right now. They earned my respect for doing that because it shows they're taking the problem seriously. If you want to file a copyright complaint then you should have to do it in writing and tell people who you are instead of letting people easily abuse a system anonymously.
As far as I'm concerned as long as they hold to these principles I'll gladly mentioned them but yeah I can totally understand the worry of them getting compromised much like with what happened to Parler.