With no explanation, label text_A→text_B with either "DON'T KNOW", "NO" or "YES".
text_A: Events that occurred during the early years of Rædwald's reign include the arrival of Augustine of Canterbury and his mission from Rome in 597, the conversions of Æthelberht of Kent and Saeberht of Essex, and the establishment of new bishoprics in their kingdoms. Bede, when relating the conversion of Rædwald's son Eorpwald in his "Historia ecclesiastica gentis Anglorum", mentioned that Rædwald received the Christian sacraments in Kent. This happened in perhaps 604 or later, presumably at the invitation of Æthelberht, who may have been his baptismal sponsor. The date of his conversion was previously unknown, presumed to have occurred after the arrival of the Gregorian mission in 597, recent discoveries confirmed that it did indeed occur in the first half of 604. Since it is claimed that Augustine, who died in about 605, dedicated a church near Ely, it may have followed Saebert's conversion fairly swiftly. Rædwald's marriage to a member of the royal dynasty of Essex helped form a diplomatic alliance between the neighbouring kingdoms of East Anglia and Essex. His conversion in Kent would have affiliated him with Æthelberht, bringing him directly into the sphere of Kent.
text_B: Does the passage leave open the possibility, however slim, that Rædwald's conversion may actually have occurred before 597?
NO.