The longer answer is: I was able to find some information, but I don't know if it is correct. I used the search engine Copilot. It uses artificial intelligence to consolidate reliable sources across the Web to create summarized answers. I asked Copilot about how long the "D" that is appended to tickers after a reverse split remains, and got the usual answer, which is that the "D" is typically removed after about twenty trading days. But then I asked the following question:
This is the answer Copilot generated:
Copilot provides source links with its answers, so I checked the links it provided. But I couldn't find the specific source of the first sentence about the company making the determination. However my understanding is that Copilot digs deeper than just the sources that it lists. If those sources list their own sources, as these did, apparently Copilot checks into the deeper links as well and gleans information from them, sometimes going multiple levels deeper. I tried a few deeper sources, and still wasn't able to find anything about the company making the determination.
The advantage of AI is that it has the resources to dig deeper and deeper into sources that branch out farther and farther. I don't have that kind of time or patience. So I didn't find the source, and I don't know if the information about the company making the determination is accurate or not.