The particular case discussed there (Poe v. Ullman, 1961) cites the Muskrat case and explicitly refers to "jurisdictional" questions, for example:
"The restriction of our jurisdiction to cases and controversies within the meaning of Article III of the Constitution, see Muskrat v. United States, 219 U.S. 346 , is not the sole limitation on the exercise of our appellate powers, especially in cases raising constitutional questions"
https://caselaw.lp.findlaw.com/cgi-bin/getcase.pl?court=US&vol=367&invol=497.
Perhaps "jurisdiction" for article 3 purposes is not best described as "subject matter juridiction," I dunno, but, whatever, it seems to be a matter of jurisdiction, not merely "standing."
Addendum: After looking at this Poe case a little closer, it seems that they are suggesting that the "actual controversy" limitation upon judicial review may not be so much "jurisdictional" in the strict sense as it is a self-imposed limitation for the sake of good jurisprudence: