No they won't. When a PC is added to a LAN segment there is no need for a gartuitous arp. The PC will use arp to resolve -
1) the mac address of any other device in the same vlan
2) the mac address of the PCs default gateway
A gratuitous arp is generally used when a device needs to update other devices that the mac address to IP mapping has changed. Because arp entries are kept in a cache they take a certain amount of time before they are removed or renewed. If during that time a device in the arp cache changes it's mac address the PC would not be able to communicate with it because it would still be using the old mac address. A gratuitous arp solves this problem.
You often see gratuitous arps being used in failover situations where the stanbdy device becomes active and because the standby device is using a different mac address it needs to tell all end devices of the new mac to IP address mapping.