The South Koreans have a robust submarine launched cruise missile capability and like
ananda, I too would assume that Indonesian submarines based on the same design are fitted for but not with this capability. Under the MEF, it would not be a priority until Indonesia acquires more of such submarines (when the magic number 9, as a threshold, is reached).
At this moment there are no indications that the Type 218SG from Singapore are to be armed with anti-ship/land attack cruise missiles.
Singapore discloses further details of Invincible-class submarines | Jane's 360.
You are correct, submarine launched cruise missiles is a capability that Singapore is unlikely to field (in the immediate future, as it may trigger regional sensibilities / arms race for this class of weapons). To save money for our limited defence budget, my guess is that we don’t want to field such type of highly offensive capability, yet — as it will increase regional tensions for so little gain. IMHO, it’s not a priority given the SAF’s more pressing needs in other areas.
Sorry for going slightly off-topic below, to answer the questions raised in this thread, let me state 3 points:
(i) My understanding is that the Singapore Navy is concerned about the launch signature of a submarine launched cruise missile, which will give away the position of our submarine during a patrol, for so little reward — as we have other cheaper means to achieve the same effects. For the Singapore Navy, a submarine is an intelligence gathering asset (that is by design supposed to be on station for weeks on end). It can attack but that is not it’s most important role for us. Plus, we don’t have the money to invest in a larger submarine force (as we currently plan to remain a four Type 218SG sub navy). IMO, there is a strong preference for air launched or ship launched cruise missiles, due to inherent balanced fleet design limitations of Singapore’s limit in its ambition for its tiny undersea force.
(ii) IMHO, there is a strong tendency for Singaporean fanboys to over-estimate or mis-understand the nature of the SAF’s capability developments.
(iii) For the foreseeable future, Singapore will develop capabilities in smaller increments, compared to current leaps, with the current round of introduction of new classes of weapons. The focus till 2030 should be on sustainment, the number and duration of patrols as a defence output. It is also important to know that Singapore does not want to be seen as too capable, as the US or Australia will pressure us to do more in their future adventures. Singapore wants to be just capable enough to deter against
Malaysian mis-calculation till 2061 (or what Dr Ng calls a ‘sweet spot’ of capability development) and also to work with Australia and the US. But Singapore would want to limit our involvement in supporting American or Australian operations, via the deployment of forces for peace support operations.