By the way, Merriam Webster doesn't even recognize "expat" as a noun
Who's Merriam Webster!
Actually Singapore is a punishment posting, it's actually worse now than 1970. I sympathise with SMS and his family 100% and I also know some Indians that moved here back in 1970, they still go back home to India quite regular for 6 months as they have retired now too.
Singapore is an experience no more and no less, it's home as long as you make it your home, but it isn't a part of your identity the majority are expatriates.
They will keep running away from their NS duties, until they find talent to fix the problem.
Wikipedia is so damn unreliable, anyone can post too it, the posts are censored of course, but lot's of information is wrong and not factual, mainly because the vetting is only done by unpaid moderators.
Though this is fact!
There is no set definition and usage does vary depending on context and individual preferences and prejudices
The lower paid worker is not an immigrant he's an expatriate fact, until he takes up PR on a local income. He then becomes an immigrant, but not of equal standing in Singapore.