Technically, nothing would prevent them from doing so. I'm not sure it wouldn't be a good thing.
But if it comes to the point where they feel they need to, they've already lost the dominance game.
Remember, the bulk of the network will be made up of people using essentially "spare" resources, i.e., over-capacity that they would likely have anyway and not be using, or at least not be fully using. Data centers would be having to put in place or divert resources that they had targeted to make income in and of themselves.
Yes, the data centers have huge capacities, but even they won't be able to amass the numbers of nodes necessary to monopolize or control the network, especially once the network gets established, and till they see that happening, I doubt they'll divert resources from their current profit models. We're just marginal dreamers on the fringes, as far as they're concerned. By the time they see it coming it will probably be way too late.
For them it would be relatively expensive compared to what they get out of it. That many nodes running on the network would actually give it pretty good stability and fast functioning. Yeah, they'd be getting a pretty big portion of safecoin, but what's unfair about that? Look at the amount of resource they'd be contributing!
Others will be using the network just because of its features--as it builds out, anyway. Everybody would be getting safecoin, too, despite data centers getting a large portion of it. But again, the facility they give to the network will make the safecoin worth more, and more individuals will join, both for the use of the network and getting safecoin. Also, all that resource will drive down the farm rate, making their contribution even more expensive to them, while everybody else will have little if any increased overhead.
The point is that even with them putting all that resource into the network, they don't actually get central control, just a larger part of participation, which means more resources for network functioning.
Centralization is about control. The network doesn't actually disincentivize centralization. Hopefully it makes it impossible.