Having been forwards coach since 2019, Rowntree was named head coach in 2022, changing Johann van Graan.
The previous England prop led Munster to the URC title in his first season – the membership’s first trophy in 12 years – however parted methods after losses to Leinster, the Stormers and the Sharks.
“It’s huge information, clearly, as a result of it doesn’t occur fairly often,” added O’Gara, who has been in command of La Rochelle since 2019.
“When one thing like that occurs, everybody is clearly taken without warning and needs to know what occurred, and I might be in that class too.”