This is a publication by @JimBaumann in ARCUSER.
In 2008, the National Geodetic Survey (NGS) announced in its 10-year plan the replacement of the country’s two national datums: North American Datum of 1983 (NAD 83), the geometric datum used mainly for horizontal positions, and the North American Vertical Datum of 1988 (NAVD 88), the vertical datum used for determining orthometric heights (elevations).
“We are leaving behind forever the idea of static, unchanging spatial reference systems. This has been well-known in the geodetic community for some time."...read more about this activity below...
https://www.esri.com/about/newsroom/arcuser/moving-from-static-spatial-reference-systems-in-2022/
