Most factories have had in-house networks for decades. Ordinary CAT-5 cable works quite well in electrically noisy industrial environments, because it's a differential signal on twisted pair. In industry, the big problem is getting all the gear to interoperate.
There's also what's called "machine to machine communcation", much of which takes place over low-cost wireless pager networks. Many industrial air conditioners, elevators, and vending machines are regularly sending their short, boring, but important messages to a server. There's even M2M over Iridium two-way satellite paging, for oil wells and such. That works anywhere you can see the sky.
That says: “actively drive the reshaping of industry, as it combines aspects of the physical, virtual, IT and cybersystem worlds to help create a new working environment of integrated productivity between worker and machine. It represents a highly dynamic point of achievement, where every company, whether large OEM, major tier supplier or small job shop, can benefit from the technologies and the communication platforms emerging in the market today, some at the speed of light.”
Last year, the OPC Foundation seemed to be "lobbying" for OPC UA to play a similarly key role in IIRA as it now has in RAMI 4.0, but that did not come to pass.
I expect that IEEE P2413 will use IIRA as a starting point. Perhaps OPC UA will be "blessed" as one of several options for the communications layer, but we'll have to wait and see.
There's some good stuff in there as well – I leave it to you to sift. In all fairness, the quote you gave isn't by the post's author, but rather consists of the words of a VP at Siemens (as quoted by the post's author).
There's also what's called "machine to machine communcation", much of which takes place over low-cost wireless pager networks. Many industrial air conditioners, elevators, and vending machines are regularly sending their short, boring, but important messages to a server. There's even M2M over Iridium two-way satellite paging, for oil wells and such. That works anywhere you can see the sky.