No, if the short paper is not longer than a two-column two-page paper. If the ‘short’ paper is longer than that, but no longer than half of the IJCAI paper, then the extension must be significant enough. The call for papers mentions:  “For anonymity of the IJCAI-ECAI 22 submission, in the citation please hide the authors’ names, and hide the place where the abstract got published. However, you need to mention that this is an extension of a published abstract, and submit the published abstract as supplementary materials (with authors’ names/affiliations and publication venue removed). For example, you should mention: This submission is an extension of a published extended 2-page abstract [AAA]. Ref-AAA: XXX. Short paper title. YYY, 2020. [see: supplementary file]”