If the challenge here is on conceptual framing of wild lands, if there were to be any movement from the word and concepts tied to "wilderness", why not something like "stewarded"? This recognizes, for example, historical Indigenous practices of managing land without allowing for plunder or party. Instead, it elevates wilderness as something to be protected, cherished, and looked after - also in opposition to the neglect of "wilderness".
I used to love the word "stewardship" because I thought it would resonate with Christians. Over time I learned that it does resonate with Christians, but in a bad way: too many of them see stewardship as extremely temporary, and they feel like there's a deadline to make the most use of land before God blows the whistle and brings this realm of existence to an end. I no longer think that environmentalism can constructively engage with Christianity. It's always going to be a fight.
Unfortunately you're right about that, as much as I like the word disconnected from those views, preconceptions about earth's apocalyptic doomsday may instead lend to "careful plunder", in a "stewardly manner". Okay, how about "Natural Sanctuaries" and the "Bureau of Land Kinship"? That may emphasize the sacredness of the land itself rather than the tending of it, which is more open to interpretation.
Making anything sacred outside of Christianity (and other established religions) offends more people and makes the fight harder. I think we should concentrate on practical, inclusive arguments about the environmental, ecological, educational, and experiential benefits of keeping large areas of land free from development and industrial exploitation, and create a hierarchy of management from maximally protected / minimally exploited areas down to fully exploited areas that have little ecological value but provide a different value such as timber production or recreation.
