I assume since you used an "sde connection" to import the feature class, you used some ArcGIS Desktop tool. There are many that can copy/import data, so I won't guess which one specifically.
As covered in ArcGIS field data types—ArcGIS Help | ArcGIS Desktop ,
Geometry
In ArcGIS, the geometry data type indicates the type of geometry—point, line, polygon, multipoint, or multipatch—the table stores. The field stored as geometry type is called SHAPE when created through ArcGIS.
When you say the table has values "like 0xE6100000010CF091A1F8EB67354050B8D91D27644440", I am guessing you are looking at the table outside of ArcGIS, in SQL Server Management Studio for example. If you are were looking at the table from within ArcGIS, you would see values line "Polygon" in the Shape column. The value you are seeing is the SQL Server CLR serialization format that MS uses to store GEOMETRY and GEOGRAPHY in SQL Server.
The short answer to your question, i.e., is there "a way to get that bytearray using a SearchCursor," is no. The ArcPy cursors work with several geospatial data formats (WKT, WKB, GeoJSON, Esri JSON, etc...), but there is no property or method for returning the native binary format that MS uses for storing spatial data in SQL Server.