The climatic optimum you refer to was cooler than today. From the wiki you reference:
A study in 2020 estimated that the average global temperature during the warmest 200 year period of the HCO, around 6,500 years ago, was around 0.7 °C warmer than the mean for nineteenth century AD, immediately before the Industrial Revolution, and 0.3 °C cooler than the average for 2011-2019.
David Attenborough was another skeptic, but he was eventually convinced by the weight of evidence.
Perhaps we should praise them for being willing to change their minds when so few people seem able to.
TLDR:
transfer of 155 parthenogenetic embryos generated two live offspring. Both had body weight similar to that of controls at birth and survived to adulthood.
Seems like there are still a lot of unknowns in this process, so caution is warranted.
https://m.youtube.com/watch?v=amn3kn0XPLQ