It doesn't change the fact that they can put a large percentage of the total supply in their custody, and the question is, "What is the threshold before it becomes truly concerning"?
This is important now and from the very beginning. Once it became apparent that bitcoin had become an important element in the world of finance, it became easy to predict the interest of large corporations. We have been seeing for a long time how bitcoin is being bought up even in view by the thousands and tens of thousands, and how many more secret purchases.
But changing the original rules of the supply-limited game could change everything, because bitcoin's conservatism gives it prestige and a level of credibility. Trying to fit in with momentary interests can change everything, and we should not listen to those who are thinking about abandoning the idea of limited issue.
Actually no, I'm personally NOT for the debate that Bitcoin should have a hard fork to change the supply cap. I believe that part of the protocol is ossified. I'm asking "what is the threshold", a question/topic that's admittedly a difficult issue. To put it in an extreme situation, if 90% of Bitcoin's supply was under the custody of a cartel of 10 asset managers, could it be said that Bitcoin has failed?
To put that in context with this topic, if truly twelve of the twenty largest banks and asset managers truly want to accumulate as much Bitcoin as they possibly can, then $500,000 per Bitcoin is not truly that high.