Check if the first block in a Matrix field matches one of an array of types
When you call entry.newsArticleContent.one().type, what you're getting is an instance of craft\models\MatrixBlockType (https://github.com/craftcms/cms/blob/develop/src/models/MatrixBlockType.php)

It just happens to have a __toString() method that will print out the handle when it's requested, but the if comparison you're doing is using the entire MatrixBlockType instance.

What you're looking for is:

{% if entry.newsArticleContent.one().type.handle  in ['fullWidthImage', 'imageGroup'] %}