The Mexican driver initially struggled to adapt to Super Formula machinery without testing and failed to escape Q1 elimination for two rounds in a row, but scored his first points at Okayama amid an overall improved showing.
O'Ward had previously expressed his desire to continue racing in Super Formula in 2020, but his replacement by Vips plunges the future of his Red Bull ties into doubt.
Red Bull motorsport advisor Helmut Marko visited Japan in August to discuss the energy drink brand’s future in Super Formula.
It is believed that Red Bull will continue to field two drivers in the series in 2020, with Vips being considered for a full-season drive.
The other seat could be retained by Lucas Auer, who has enjoyed an impressive maiden campaign with the B-Max with Motorpark team, including a podium finish at Sugo.