I think all big tech companies own some bitcoin. Some of them have already announced this, others will announce it soon, and still others - perhaps I will remain silent and will not speak about it publicly. In any case, the temptation to buy bitcoin is too great not to use it. In addition, there are still a lot of private investors who have not yet publicly announced this, but they can do it at any time. Each such recognition makes Bitcoin more attractive to others.
I believe there are a lot more companies or individuals that are holding good amount of bitcoin but of course some are not disclosing their holdings for varied reasons like safety, avoidance of regulatory laws, or just to keep silent about it. And you can't blame them, after all, you can own your own bitcoin without alerting anyone. It is your own prerogative if you will disclose it to the public or not.
But with the disclosure of some top companies about owning bitcoin, gives more interest from the public. That's the reason why those companies publicly announcing their bitcoin holdings, are giving motivation or inspiration for others to buy their own bitcoin.