Is the 30K mile maintenance neccessary for Chevy Silverado?

I'd rotate and balance the tires, change the DexCool antifreeze, do an oil change if it's due and check the air filter.

Change the ATF and ATF filter at 60,000 miles.

$800 for a 30,000 mile maintenance is stupid and expensive.

Nope. It's just in the manual to strip you of $800, which matters so much for something that costs over $30,000.

Of COURSE it's necessary! Bringing it to the DEALERSHIP is not. Go to a local mechanic. It's a GM. Everybody repairs and works on GMs.

If the 30K service, as shown in your vehicle's paperwork, includes all the transmission fluids, brake fluid, clutch fluid, and transfer case (if 4X4) fluid do not put it off. However, all the 2015 and 2016 schedules I find for gas engines show those at the 45K mile interval. Without knowing the year, trim level, and engine we can't say much more.

Edit - 2014 Silverado 1500 LT, 2WD, Crew Cab... got it. Check out the source. The big service is not due until 45,000 miles. I guess that answers your question!

Find an independent shop.