I guess you’re right, I always refer to them as SE Asia but it’s technically considered East Asia. Thanks for the correction.
This phrasing seems odd, considering that those two countries are firmly in East Asia, and would not be considered as a part of SE Asia by any definition.
It’s a habit of thought that I should break because it’s not really a common way to look at Asia, which makes communication difficult. It’s almost certainly a habit derived from discussion about the US, which is often discussed as four quadrants plus “the midwest,” which is really the center.