The writing was on for the wall for 120-Test veteran during the June window when he was dropped to the bench for the clashes against Fiji and Scotland.
Coach Michael Cheika said at the time Moore was still the team's captain, with Hooper only taking on the responsibility on match day, and insisted he had a role to play at the World Cup.
However, Moore appears to have changed his mind at some point since.
The impact of a gruelling pre-Rugby Championship training camp in Newcastle, formulated because of complaints Australian Super Rugby players weren't being prepared well enough for Test rugby, may have played a role.
"Stephen still has a big role to play within the team. This isn't a farewell right now - he's fully committed to getting the gold jersey back to the top this year," Cheika said.
Exactly who will succeed Moore at hooker in the long-term is unclear.
Tatafu Polota-Nau replaced him at No.2 when he was benched in June but the Western Force veteran is 32, while the only other hooker in the squad is under-20s star Jordan Uelese.
NSW's Tolu Latu is injured while Andrew Ready, Moore's highly rated Reds teammate, has stalled in his development this year.
STEPHEN MOORE - CAREER AT A GLANCE
* Super Rugby debut in 2003 vs Bulls
* Wallabies debut in 2005 vs Samoa
* Became Wallabies captain in 2014 vs France
* Played at World Cups in 2007, 2011, 2015
* Tests: 120 (96 starts)
* Tries: 8
* 10th most capped international player in history
* Super Rugby appearances: 177
* Super Rugby tries: 23