The iOS 11.4 Update has been released and does not mention any new Apple Pay Transit Cards. Of course iOS 11.4 does not fix the long running iPhone X Suica problem.
The iOS 11.4 developer preview included China Express Transit card support for Jiangsu, Shenzhen, Wuhan and Chongqing transit cards in addition to the Beijing and Shanghai cards rolled out with iOS 11.3.
Apple testing of a iOS 11.4.1 update is already underway
, there is still hope that the iPhone X Suica problem will finally be fixed along with new Apple Pay Transit Cards for China before iOS 12 arrives later this year. I do not think iOS 11.4.1 or any iOS update will fix the iPhone X Suica problem. My view is the problem is caused by a iPhone X NFC hardware flaw that cannot be fixed by software.