[oneplane]

NSX-T and what hyperscalers do is essentially orchestration of things that already exist anyway. The load balancing in NSX is mostly just some openresty and Lua which as been around for quite a while. Classic Q-in-Q and bridging also does practically all of the classic L2 & L3 networking that tends to be touted as 'new', while you could even do that fully orchestrated when Puppet was the hot new thing back in the day.

Some things (that were created before NSX) may have come from internet exchanges and hyperscalers, like openflow, P4, and FRR, but were really not missing parts that were required to do software defined networking. If anything, the only thing you really needed for SDN was Linux, and the only real distinction between SDN and non-SDN was hardwired ASICs in the network fabric (well, not hard-hardwired, but with limited programmability or 'secret' APIs).