It makes little sense to sync to the grid when the generator is only
used when the grid is down
I don't know what large DC do but at our large sites we normally get
power cheaper in exchange for a load shed agreement.
When we got the call we ran some/all of the load on generator so the
grid could flatten peaks.
At our tv/radio transmitter sites there were no UPS so a break would
disruptive. SOP was to run up the gens, sync then parallel the grid.
DC just treat it as a power failure with a short break on non UPS