Embolo received a second yellow card during the second half with the match level at 1-1. Argentina struck twice in extra time to beat 10-man Switzerland 3-1 in Kansas City.
The 29-year-old had gone down following a challenge by Leandro Paredes, and referee Joao Pinheiro initially booked the Argentina midfielder. But the VAR informed the referee that Paredes had not committed a foul, and Pinheiro booked Embolo instead for simulation.
IFAB clarified that while the VAR can intervene in relation to mistaken identity when the wrong player has been booked, it cannot be used to review the offence itself.
"A yellow card (caution) which is not a second yellow card can only be reviewed to identify the player who committed the offence that was penalised; the offence itself cannot be reviewed/changed," IFAB said.
"The use of the mistaken identity clause to deal with simulation during the FIFA World Cup 2026 was well received and will be included in the detailed review of the VAR protocol... however, it may not be used as such until that review is concluded."
Switzerland coach Murat Yakin said the rule behind Breel Embolo's sending-off was “unacceptable” after a loss that stopped them reaching the World Cup semi-finals for the first time.
“It destroyed our game today. We have to accept it, but it's painful to lose that way,” Yakin said.
Defending champions Argentina lost the final to Spain.