How long has it been in place for, that sleeping in the same room until 6/12 months was safe? When was this implemented?

https://rednose.org.au/article/room-sharing-with-baby
This information was initially posted on Red Nose (then SIDS and Kids) web site in 2008 & last updated by Red Nose National Scientific Advisory Group in 2016. A recent amendment was made to recommend room sharing for first 6 months (from 6-12mths) to reflect the importance of the critical development period of the first 6 mths of life, in relation to the risk of SUDI (Sudden Unexpected Death in Infancy)