Hong Kong backs down on extradition Bill after protests
channelnewsasia.com
channelnewsasia.com
It's a tactic to buy time. If the HK government can gain support from the Chinese government, it will likely push ahead with the bill again regardless of the reaction of the local population.
The ambassador's comment was the only thing he could have said, really. I.e. that it is not for the central government to draft HK legislation.
It's not a question of supporting the bill but of question of supporting the HK government despite the unrest it will create.
The Chinese government may conclude (and may have concluded) that at the moment there are much more pressing problems and that they could do without riots in HK.