CONMEBOL's resistance to doubling the frequency of World Cups is striking given its president, Alejandro Domínguez, proposed the same concept to FIFA in 2018.
Bayern Munich coach Julian Nagelsmann was as concerned about the impact on FIFA's flagship events if the frequency was doubled.
Sabitzer, 27, scored 52 goals in 229 appearances for Leipzig but was out of contract next June.
German Super Cup: Robert Lewandowski, Thomas Mueller on target as Bayern Munich beat Borussia Dortmund
New coach Julian Nagelsmann has earned a trophy, which Bayern also won last year against Dortmund in Munich, with his first win in charge.
David Alaba, Jerome Boateng, Douglas Costa and Javi Martínez were among the players to leave Bayern in the offseason.
After two successful seasons with RB Leipzig, Nagelsmann, who turns 34 later this month, has taken charge of Bayern, replacing Hansi Flick, who is Germany's new head coach.
Julian Nagelsmann joined Leipzig in 2019 from Hoffenheim and led them to the Champions League semi-finals last season.
Leipzig cut the gap on Bayern to seven points with three rounds remaining and can mathematically still win the title if Bayern follows its surprise 2-1 loss at Mainz with a collapse.
Flick has been linked to the job of Germany boss with Joachim Loew set to step down after this summer's European Championship.