I've been subscribed to his Twitter account for some time. You may assume that I am not an acolyte of his, but I like to know what people are saying and thinking--especially those with whom I disagree.
It's fair to say that it has been a relentless stream of nonsense about Coronavirus as a method of societal control for most of this year, but, honestly, I don't see why his talking nonsense on the Internet should result in his being gagged.
Which is to say, an awful lot of people spout nonsense on Twitter without sanction. Part of that is related to the respective size of audiences, but another part is that Twitter 'picks its causes'. You may think that in this instance they have a solid case (I don't, but you might), but I guarantee you that an issue about which you personally hold strong views will loom into view before very long. I, personally, do not want TechGiants deciding the issues on which I can and cannot dissent from the general consensus.
It's bad enough when democratically elected governments start doing it; unelected megacorps have even less reason to defend my ability to speak my mind.
If David Icke's speech breaks the law, then an injunction and/or a conviction should be sought. We cannot and should not be gagging people to protect idiots from themselves. If the harm overspills the weak of thought (as with anti-vaccines and anti-science in general), then our governments should grasp the nettle and address it, not the bien-pensants of Silicone Valley.