You can't trust any of the 'mega-corp' so these donations will have handcuffs.
One thing not said explicitly is that the Fediverse needs a funding model and I believe it will die without one.
I know people are down voting this because of what you suggested. But I don't think we should be afraid of taking about money and funding it. The Fediverse is not free to run, or develop, so without money coming in, it's going to die. We shouldn't he afraid to talk about any options of funding. Even a conversation like this, where a lot of people are against it, can lead to other ideas that are more palpable.