I think they are just excited with the mere thought of a big company putting in their trust and money into bitcoin the way they do that it justifies or validates their own decision to invest as well. This also increases positive general opinion towards bitcoin. I know we shouldn’t have to follow big companies or any other individuals but maybe they still look for some validation from “experts”.
The fact that we don't need no validation from all this traders and gambler's who are coming into Bitcoin with the sole aim of maximizing the opportunity that comes with Bitcoin, if you checked very well you know that most of those companies CEO like microstrategy have one time spoken against Bitcoin in the earliest stage some even mentioned that Bitcoin is a bubble that will burst any moment but now that their have seen that Bitcoin have mentained a constant value gains surpassing most companies in market cap.
Now they are coming back to support their investment since their now holds a lot of Bitcoin in their reserves and now their are advocating for the mainstream and institutions investors just to increase the value of their investment.