Historically many U.S. national monuments were upgraded to national parks after a few years, e.g. Grand Canyon (monument 1908, park 1919), Jackson Hole (monument 1943, park 1950) or Glacier Bay (monument 1978, park 1980). Surely it would be even easier today to upgrade a monument to a park, given greater public interest in conservation and a more powerful environmental lobby than existed back then?
The Wilderness Society, among others, appears to believe that the president has no authority to reduce or eliminate national monuments, only to create or expand them. If so, upgrading a monument to a park is superfluous in terms of the protection offered, and only needed to provide more amenities to visitors. However, I don’t know how widespread this view is. Although I am not a lawyer, it seems to me that once Congress designates a park, that would bind the president, but until then, how could a former president’s declaration bind a future president?
I’m having trouble locating any effort, because all my searches turn up Rep. Chris Stewart’s "too little, too late" proposal that post-dates the 2017 reduction and would therefore include only the reduced monument.