I'm sure in the handful of cases where they have a genuine bulk contract on paper with a large firm that states they'll be in breach if they train on it, they do abide by it.

But unless you are one of those you mentioned and a few others you probably aren't notable enough to care about. Everyone who uses their services directly, paying or not, is surely ignored in that sense. I wouldn't be surprised if there's a team of their own lawyers ready to interpret their EULA in fascinating ways.

And out of those three I'd only probably assume Apple is the only one who doesn't use the data given that they've built up privacy as a selling point, MS and Google probably train their own models on it themselves.