I think it is enabled automatically for free for the first year, but does not automatically renew, because it is not free after the first year.
Re:Amazon's customer service backdoor
by longnguyen on Sunday January 24, 2016 @09:30PM
(#10965258)
Same here. I've registered a bunch of domain names with Namecheap over the last year and they all had whoisguard turned on.
I registered a new domain with Namecheap just last Thursday and it had whoisguard automatically turned on.