From what I can see in a quick search (and from this presentation), Netflix only uses FreeBSD for serving video and they run these servers themselves in their own datacenters I guess. In contrast their apps on EC2 use Linux [0]. Sounds like the time has not yet come when AWS is paying anyone full time to support FreeBSD on EC2.
[0] https://twitter.com/brendangregg/status/1412201241472471048