Is there a way to convert the PostGIS geom type to the ST_geom type when using a trigger in PostgreSQL that will insert data from a PostGIS database table into an ESRI database table?
The easiest way would be to copy the PostGIS geometry feature class back into the geodatabase and use the default geometry storage (ST_Geometry).
You could identify the new records within the PG table and append them to the ST table via Python/ArcPy or look into the ST_Geometry commands available: ST_Geometry—Help | ArcGIS Desktop . The latter may require a few different steps.
Is this the direction that you are looking for?