"Zero Latency"?
* for sufficiently large values of zero
They've basically discovered TCP Performance Enhancing Proxies, used for decades for space communications.
The claim seems correct with those caveats, though is a bit "click baity" without them.
I think it is a valid claim, but only for a rare set of use cases where the significant caveats regarding delivery & response are OK. Though of course those caveats are not as heavy as they might at first seem if the link between client and proxy is strong and reliable, because the proxy will be performing the full handshake and can manage redeliver on error and other such things - but the client doesn't need to worry about any of that.