I can think about a few arguments to include all original authors as authors of the corrigendum.

<ol><li> They actually work on the corrigendum by reading your manuscript and making comments;
<li> The corrigendum has no "primary" value without the original paper, it can be considered as an extra chapter. It does not really matter that you worked on this chapter more than they, since they probably contributed to other parts of the paper;
<li>How would it look if you publish corrigendum without them? A little bit like "These senior guys screw it up, but luckily I able to fix it", isn't it? Do you really think this is an impression you want to make considering their contribution?
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