Having been forwards coach since 2019, Rowntree was named head coach in 2022, replacing Johann van Graan.
The former England prop led Munster to the URC title in his first season – the club’s first trophy in 12 years – but parted ways after losses to Leinster, the Stormers and the Sharks.
“It’s big news, obviously, because it doesn’t happen very often,” added O’Gara, who has been in charge of La Rochelle since 2019.
“When something like that happens, everyone is obviously taken by surprise and wants to know what happened, and I would be in that category too.”
