100 employees is a lot. There's a multiplier effect, even for those commuting from a distance.
No, it is not, particularly because of the type of facility.
This is a 24x7 non-public facility that operates every day of the year. With weekends, vacation, sick time, etc. plus the fact that there are probably three shifts (day, swing, graveyard), there are probably no more than 20-25 people working at any given time, and most of whom are working in hours that aren't related to nearby retail businesses.
Heck, there's a good chance that there might only be 5-10 or so bodies on site, with a lot of people working remotely (and willing to hop in a car if something seriously broke). Let's face it, if you're the senior Oracle DBA and you've wedged the server (unlikely), you can always get some Level 1 Sysadmin to reboot the hardware. If something really goes awry, Oracle DBA will drive to the facility and arrive around the same time as the Oracle system engineer arrives.
As a non-public facility, this location does not need the ancillary services or businesses that a public facility would attract. It's not like there are hundreds of visitors per day.
Let's face it, if this was a public location (retail store, restaurant, museum, whatnot) employing a hundred people during normal business hours, yeah, a hundred employees might actually be significant.
But it's not that type of location.
Heck, this place won't even generate local sales tax since it's not a retail business operation.
A small hotel would have more impact on the local community over a data center.
Apple's data center's largest impact on the local economy in the long run will probably be a few extra property tax dollars.
The benefits to local business will be mostly tied to the construction phase of the project. In a one-time deal, one local company will probably score the contract in paving the road to the facility. For a short while, a roach coach will probably service the construction workers on the job site. After the facility is complete, there will be very little human activity at the site itself.