Singapore had repented and invited China to bid for KL-HSR construction.

http://en.people.cn/n3/2017/0612/c90000-9227233.html

http://sg-stock.blogspot.sg/2017/05/bad-news-china-has-isolated-singapore.html

http://sg-stock.blogspot.sg/2017/05/the-fight-for-kl-sg-hsr-is-not-over-yet.html

Singapore had repented because of Japan's public expression to join the BRI and was rejected by China. Singapore knew that it couldn't support Japan anymore after seeing Japan being snubbed by China unless SG wanted to be ostracized completely by China.

http://sg-stock.blogspot.sg/2017/06/what-is-japan-thinking-it-just-shows.html

Furthermore, HK has just joined AIIB.  SG has always been looking at HK as a direct competitor in this region as HK is a much bigger financial hub than SG.  HK will be able to capitalize on its financial expertise to provide financial assistance to the BRI project through AIIB which SG is also targeting.

http://sg-stock.blogspot.sg/2017/06/what-joke-singapore-to-help-bankroll.html

http://gbtimes.com/business/hong-kong-becomes-aiibs-first-non-sovereign-member