Is Cūḷa Suññata Sutta a prelude to Bahiya Sutta?

The Cūḷa Suññata Sutta gives a progressive means of experiencing sunyata. The Bahiya Sutta (UD) tells of an interaction between Buddha and the Brahmin Bahiya - Buddha advises Bahiya to get right on the surface of things without any dwelling (bhava): *“And since for you, Bāhiya, in what is seen there will be only what is seen, in what is heard there will be only what is heard, in what is sensed there will be only what is sensed, in what is cognized there will be only what is cognized, therefore, Bāhiya, you will not be with that; and since, Bāhiya, you will not be with that, therefore, Bāhiya, you will not be in that; and since, Bāhiya, you will not be in that, therefore, Bāhiya, you will not be here or hereafter or in between the two—just this is the end of suffering.”* Is the admonishment given to Bahiya a corollary to the **themeless concentration (signless immersion of the heart)** described in Cūḷa Suññata Sutta? If Bahiya has not realized sunyata can he adhere to Buddha's words?