His childhood sweetheart has absolutely nothing to do with it. And yes, the ltvp for the foreign spouse would be the 'normal' route when married to a Singaporean anchor.
However.
Said foreign spouse renounced his PR (or should I say his parents did it for him) in order to specifically avoid NS (otherwise why would they renounce his and not their own? Doesn't make a lot of sense and one would have to be a 'kin idiot not to see why it was done. It will be plainly obvious to ICA and that will be all she wrote.
No, I think his parents have screwed him royally. His is a classic case that I've been warning people of for 12 years on the board. But, people see to always think they are smarter or they are never coming back. Such is life, more than one son hates his parents for screwing up their lives without their input.