Do you have any reason to believe it is? The article contains interviews from spokespersons of some of the charities in question and Bloomberg asked Facebook/Google for comment. Surely if it was simply matching donations, someone in PR for one of these organizations would have derailed this entire article by pointing that out?

There is a long standing tradition of companies funding "third party" groups with essentially the opposite naming to what they're actually lobbying for.

FUD / message control / obfuscation is the name of the game.

Non-profits should be automatically named <sponsor>'s <name of group> - that would at least make it a little more obvious whose message you're getting.