EDIT: I misunderstood "purge" in this context. I disagree that silence on moderating content is "violence" just as I disagree that anything you disagree with is "violence." But I do not believe content will be "purged" unless it's part of a movement to unseat democracy or coordinate violent actions.
He's saying that when a person don't like something, the recent trend is to just label it as "inciting violence". He then adds onto that by saying the idea of "silence is violence" means that anyone who does not speak out against the disliked thing is inherently guilty of "inciting violence" as well, so lurkers and moderates are not safe from being labeled.
Again, I disagree with what he said. However, accusing his post of threatening violence against everyone with whom he disagrees does kind of support his point.
"Parler will not knowingly allow itself to be used as a tool for crime, civil torts, or other unlawful acts. We will remove reported member content that a reasonable and objective observer would believe constitutes or evidences such activity. We may also remove the accounts of members who use our platform in this way."
https://legal.parler.com/documents/guidelines.pdf (obviously inaccessible now).