Announced as the answer to a disastrous election that saw the Peter Dutton-led party deliver its worst performance since the 1940s, party officials confirmed on Friday the review would not be published.
One of the review's authors labelled that decision a "deep regret" and said she took the voluntary assignment after being assured it would be made public.
That assurance was given when Sussan Ley led the Liberal Party, but new head Angus Taylor never confirmed he would do so since he won the leadership earlier in February.
Co-author and former NSW Liberal minister Pru Goward said almost 100 interviews into the campaign had been undertaken with people intimately involved.
"No new leader, whether of a failing company or losing football team, has ever been able to change an organisation without understanding why the failure occurred and ensuring that understanding is shared with shareholders, players and supporters," she wrote in the Australian Financial Review.
"Ley knew that."
Fellow co-author and former coalition minister Nick Minchin was even stronger in his disappointment, describing it as a betrayal of members who had worked hard for the party.
"They will be horrified by the decision to bury the review into a shocking election result," he told The Conversation.
"And many candidates who lost seats or failed in their attempt to win seats will be extremely disappointed."
The Liberals' primary vote at the federal election in May plummeted to its lowest level since the 1940s, slashing the party's representation in the 150-member House of Representatives to 43 seats.
The review probed the reasons for the low vote and poor performance among some voter groups, including women.
It also examined the long-term challenge for the Liberals posed by independents, with key seats lost to teal candidates.
A Liberal Party statement did not provide any reason for why it had suppressed the review, but said focusing on the future was more important.
"The review recognises the party's enduring strengths ... it also sets out where processes failed, where connection with voters was lost, and where we must do better," the statement read.
"The election result was a decisive defeat, we accept that verdict, we also accept the responsibility to change."