The error message, "Error 000584 Implementation of this Tool's Validate is invalid." is returned when running the Create LAS Dataset tool with a Basic license and a Spatial Analyst license.
When the error occurs with an unknown coordinate system, specify a coordinate system in the Coordinate System parameter and the tool runs as expected.
When using the Basic license in ArcGIS Pro, the 3D Analyst license must be assigned. This also works as expected with Standard and Advanced licenses in ArcGIS Pro.