The 'Unbreak My Heart' singer made the decision after Tamar's latest bust-up with estranged husband Vincent Herbert.
RadarOnline.com previously reported how the pair had a fight outside her Beverly Hills high rise resulting in him being banned from the building.
The family tour was supposed to feature Toni, 50, with Tamar and Traci Braxton, 47, as her opening acts.
But it is understood that the promoters do not want to deal with Tamar's divorce drama and were worried it might impact ticket sales.
They feared things could get messy as Tamar is still managed by 45-year-old Vincent despite their messy demise.
The couple have had a troubled past in recent times
Tamar, 41, filed for divorce from her husband of nine years last October and requested full custody of their young son Logan, 4, while demanding he get no spousal support.
At present the promoters are considering a replacement for when the tour starts on May 22, 2018.
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