NRL chairman Peter V'landys confirmed an 11-minute mystery entertainment slot before Sunday's grand final at Accor Stadium.
"I've got to tell you it'll be the highest-rating 11 minutes you will ever see, because no one knows what it is, and we won't tell until the night," V'landys told reporters.
The announcement followed backlash after talks with Australian artist Tones and I broke down; Kylie Minogue's AFL grand-final performance added to the criticism.
V'landys said the $1 million pledged for grassroots rugby league would still help disadvantaged children unable to afford boots, registration or insurance.
The entertainment act will receive some funding, but less than the NRL would usually spend.
The NRLW decider may become a standalone event next season, possibly on Friday at Allianz Stadium. Players largely rejected a third-place playoff and Indigenous All Stars match this season, though both remain future options.
V'landys said the women's game deserves its own window, adding: "At this stage of its evolution it is so far ahead of any other women's sport."