We are told that SIA are leasing 19 A330-300s from Airbus to bridge them over until their 787s and A350s arrive.
Might it be argued that they have been a bit belated in recognising the suitability of the A330-300 in the south-east Asia regional market? Consider how many airlines fly them and when they first put them into service.
1995 Cathay Pacific
These seven airlines have a combined fleet of 101 A330-300s and have been using them for a decade or so. During this time SQ looked at the A330 several times but always rejected it, preferring to 'misuse' 777-200ERs on some regional routes.
A second wave of airlines also decided that the A330-300 was what they needed. Again, these are the dates when they entered service.
2003 EVA (they actually have -200s but they use them on regional routes)
2004 China Airlines
2005 China Southern (their initial order for -200s has been followed by a larger one of -300s)
2006 China Eastern
2006 Air China (-200s)
And now Hainan is adding seven A330s.
In short, almost every serious competitor in south-east Asia chose the A330 (mostly the -300) while SQ considered it but then looked elsewhere. Now, belatedly, they are acquiring the large fleet of A330s that they could and, arguably, should have been flying ten years ago.
A rare example of SQ simply getting it wrong?