TA had been on the lookout for a new chief executive after Craig Tiley announced in February that he was stepping down this year to become head of the US Tennis Association.
Abdo's resignation comes as the NRL stands on the cusp of unprecedented expansion, welcoming teams in Perth and PNG in 2027 and 2028, respectively.
Abdo will also not be on hand to finalise the NRL's next broadcast deal nor collective bargaining agreement with the rugby league players association.
Both deals are due for renewal after the 2027 NRL season.
Australian Rugby League Commission chair Peter V'landys shapes as a contender to serve as CEO on an interim basis, having worked closely with Abdo during his six years at the helm.
Abdo took charge of the NRL in April 2020 and helped the league navigate the competition's COVID-enforced shutdown and subsequent resumption that May.
Under Abdo's leadership, the NRL has executed its daring plan to open the season with matches in Las Vegas, a deal that also runs out after 2027.
The league has introduced major changes to its rule-book on Abdo's watch, most notably introducing the divisive set-restart rule.
Abdo was also chief executive when the NRL expanded for the first time since 2007, introducing the Dolphins for the 2023 season.
Prior to replacing Todd Greenberg as chief executive, Abdo had served as the NRL's chief commercial officer from 2013 until 2020, and previously worked in the corporate sector.
Tiley had worked at TA since starting as the player development chief in 2005.
He became the Australian Open tournament director the following year and CEO in 2013 and had been easily Australia's highest-paid sports administrator with a multi-million dollar salary.
Most of the movers and shakers in Australian tennis are in Paris for the French Open, which started on Sunday.