You probably have an answer by now.
But, for the Google searches here-forward that will find this message:
yes Go keyboard has the ".com" key
It is, however, context controlled; as is all of Go keyboard.
Specifically, IF you are composing, let's say, a "login" entry that uses your Email address; then Go kbd will automatically include the ".com" key and also the " @ " key (in the lower left ) to facilitate your typing of the required format.
Otherwise the key is not present.