Currently in the ArcGIS Python API (from what I can tell) there is no geometry function which loads text from WKT format into ESRI geometry format. The closest thing that I can find is loads_xy method which handles point x, y data. But there is nothing for lines, polygons or multipolygons.
As a work around I am currently using the shapely function loads and then converting back to ESRI format as I have documented in this geonet thread
