I'm starting to wonder which company will be next? Will it be Walmart, Amazon, or Apple? What do you think will happen if one (or all) of these major companies invest in Bitcoin? Will it benefit the market immediately? Or will it take some time? Do you think such companies will control a huge portion of Bitcoin's supply, effectively making it centralized? Your input will be greatly appreciated. Thanks in advance. 
The most interesting point in your topic a question about centralization. We know Bitcoin is a decentralized cryptocurrency, but if a major part of Bitcoin accumulates by all the centralized organizations then we will face a problem. Because due to holding a major part of the Bitcoin they will able to manipulate the Bitcoin market as they want. I know if one or all of these companies invest in Bitcoin then the price would record a new ATH and also it would be a massive adaption. But most probably it would drive to centralization as you said. Rather than accumulate a huge amount, if they accept Bitcoin for payment, then it would be massive and long time adaption forever until they accept.It's already here now, its called TBTF - TOO BIG TO FAIL, once any financial instrument is a critical part of the retirement system, and/or cop-fireman pension system, then the FED will bail out every loss.
We're here now,
The irony of course is that BITCOIN Satoshi mythological narrative was that BTC was going to free us from FIAT and the system, the reality is that BITCOIN is just same-same with 100% absolute tracking, and loss of privacy.
Go figure, ahh but you all going to get rich on virtual paper.