With the Boeing 777X facing an uncertain future, SIA has decided to debut its next-gen cabin products on the A350-900LH and A350-900ULR instead- with the latter gaining a First Class cabin!

source: https://milelion.com/2024/11/04/breaking-singapore-airlines-to-retrofit-airbus-a350-900s-with-new-first-and-business-class-seats/