I'm also 100% on getting pre-check after entering my global entry KTN on the airline websites, and without a separate pre-check program application. In fact, that's the reason I got GE; I haven't traveled internationally since getting it.
One caveat - make sure that the name on the airline account and on the ticket exactly match what you have on your global entry. From anecdotes here, if you're Robert A Miller on one and Robert Alan Miller on the other, you probably won't get the pre-check.