They are a zero-trust networking solution that also traverses IPv4 NATs. Zero-trust networking is a layer above the IP layer. In an IPv6 Internet their capital costs go down, and their product remains valuable for their paying customers. (Free accounts mostly use it for NAT traversal, businesses for the zero-trust encryption.)

Their CEO has been working with (and supporting) v6 for decades both at the executive level (now) and also as an extremely capable software engineer that I personally met with a few times while we were both engineers at Google doing network measurement.