Clearly, Picard from the very start commanded a ship of war, and considered weapons or at least shields a key ingredient in conducting diplomacy and protecting the Federation. If a long mission of exploration was written out of the equation, it wasn't in search of conflict plots. It was probably simply because a long mission would have called for some sort of dramatic continuity, and the format of the show didn't cater for that.
But that's precisely what was intended, even till the end of "Encounter at Farpoint": "Let's see what's out there..." as the closing line. Q had prevented the ship going "where none [in Starfleet] had gone before...", Picard defended their right to continue on.
We had Bjo Trimble at an Aussie convention, just a short while after she'd been on that set, chatting with Roddenberry, Gerrold and Fontana, and her interpretation was that the ship wouldn't be returning to Earth, or UFP space, any time soon.
The first "Writers' Bible" stats that we wouldn't be meeting "familiar races", such as Klingons, Romulans, Andorians or other TOS species unless members of those races were on board.
Hence there were a few Vulcan extras seen during the pilot, reminding us that Vulcan stories were possible. Worf would have been the only Klingon we got to know, unless the ship happened across a Klingon ship, as it did in "Heart of Glory".
All that changed after "The Naked Now" when, after searching for the SS Tsiolkovsky
- which may well have been on their way "out there" - suddenly the huge Enterprise-D
was on a local milk run in "Code of Honor", seeking a medicine needed back on a Federation world. The "ongoing mission" beyond Farpoint Station seemingly abandoned.