Though in every example you gave, the perceived group identity power matched the individual power, I've witnessed a number of examples of appropriation that went backwards from group identity power, but have never seen one backwards from individual power.

That is, I've never seen a subordinate successfully take credit for an idea from a boss, even if the subordinate is a cis het white neurotypical etc. etc. male and the boss is not all of those things. I have seen people from nominally "marginalized identities" (but individual power) pilfer achievements from those of "privileged identities" (but not actual individual privilege relative to the pilferer).

So it's a fair point, but I think it's the wrong point.

The moral problem comes when anybody uses their power to steal an idea from someone else...period.

If you have power or visibility, it's healthy and just to use it to elevate the accomplishments of those with less power or less visibility.

And that's all, from a moral standpoint.

From a pragmatic standpoint, one might expect to find more opportunities to make a difference morally in cases where there are identity group power disparities also. But this shouldn't be the focus to the exclusion of individual power disparities, which seem, at least in my experience, to be the real enabling factor.