It’s a hard to answer because each grid will treat it differently. My own experience when trying to track some of this data down, DCs are largely having to do the same and that’s why a lot of the buildout includes behind the meter generation to make up for it.
There is not a good picture in aggregate though so it creates all kinds of narratives.
Of the data center rollouts I've been contracted to do safety systems for, ALL of them have gas turbines as part of their power infrastructure on property. They don't solely have gas, but they are mixed Solar/Gas every time.
A few of them in the future pipeline swear they will have nuclear but I don't see that coming to fruition soon.
And is that datacenter bypassing air quality regulation and backing up to a housing development? Most/all of the construction I have tracked meets air quality guidelines and fairly remote but I know that is not always the case!
There is not a good picture in aggregate though so it creates all kinds of narratives.