Hey, I was trying to figure out the equivalent of this 2.79 python snippet in blender 2.8 but no chance yet
bpy.data.meshes[0].tessfaces.add(len(faces))
bpy.data.meshes[0].vertices.foreach_set("co" , unpack_list(vertices))
bpy.data.meshes[0].tessfaces.foreach_set("vertices_raw" , unpack_face_list([f for f in faces]))
bpy.data.meshes[0].update(calc_tessface = True)
Thanks in advance