Question: We witness the closure of the tesseract once Coop successfully sends the singularity data back to Murph. And then it appears that Coop is sent back through the wormhole to our home galaxy.

Is the implication that the wormhole remained open, and only the tesseract was closed?

If so, then I imagine as soon as Coop rendezvouses with Brand, the rest of humanity will follow (at least the ones who don't prefer living on a giant cylindrical habitat)? At any rate, it doesn't seem likely that Dr. Brand would be alone for very long, which takes some of the urgency away from Coop's final voyage.

Answer: 
Depends on where Cooper Station is, which I think doesn't matter.

After returning from the first planet (Miller's planet, with the sunamis and the crazy time dilation), Coop and Brand are the same age and Murph is 23 years older (Murph is at least as old as Coop was when he left) and Romilly has gone gray waiting for them on the Endurance.

Coop and Brand stay on the same time scale relative to each other, up until the moment that they are slingshotting around Gargantua and Coop ditches Brand so that she can make it to the third planet (Edmund's planet). The closer you are to Gargantua the more extreme the time dilation. So, as Coop falls closer to the black hole, he would experience time ever slower and slower than Brand (and both of them much slower than Earth); but on the other hand Coop was only falling for like a few minutes (from his perspective) before he enters the tesseract. So it's hard to tell how much difference there is between Coop and Brand as they are both very near Gargantua but Coop was that much closer for a few minutes.

Then Coop is in the tesseract. Although gravity leaks through the tesseract back in time, Coop cannot go back in time (otherwise, he could have just told Murph what to do in person instead of having to manipulate gravity waves; for that matter, "they" could have gone back in time their damn selves, or at least sent Morse Code themselves, instead of taking the stupidly big risk that is the movie). So, I'm guessing when you emerge from the tesseract, you have not gone back in time. (You may have not moved forward in time either; at any rate Coop was only in there for a few minutes so no big loss).

After the tesseract, Coop awakens on Cooper Station (the ring habitat), and Murph is dyingly old. So like another 70 years have passed for Murph (she's like 100), and just days for Coop (since the mission started), and perhaps days or weeks for Brand. Remember also that Earth only had a few more years of life left, which means that Cooper Station was launched very shortly after the adult Murph worked out the calculations, which means that Murph grew old while living on Cooper Station, as no one was living on Earth.

All three planets on the Gargantua side of the wormhole experience significant time dilation relative to Earth (remember even Dr. Mann was marooned on his planet for so long that he lost hope and went crazy). So if Cooper Station left Earth like 70 years ago (or before Earth died anyway), it's possible that all those years did in fact pass (for Murph) in the few minutes that Coop and Brand were slingshotting around Gargantua's event horizon. Maybe Cooper Station emerges from the wormhole around the time that Coop and Brand have completed their slingshot. (Also assuming Murph's gravity calculations also allow rapid flight from Earth to the wormhole near Saturn; it will take NASA Cassini Space Probe 20 years before it gets to Saturn in 2017). So end result: Murph is old, Coop wakes up from the tesseract, and maybe Brand is roughly the same time scale as Coop. Coop picks up Brand at nearby Edmund's Planet. No need for wormhole--could be closed, could be open. Nobody knows.

On the other hand, if Cooper Station is on this side of the wormhole then same diff. Murph is still crazy old, but Coop could not get to Brand except through the wormhole, which must still be open. Again nobody knows.
Pertaining to the wormhole status.
IF "they" placed the wormhole there then you would need a huge source of energy to create it and maintain it. The Gargantua black hole would be my assumption as that source of holding it open. Maybe Jupiter is holding it open on our side?? Somehow?? So if the tesseract was removed and that energy source was removed, then it would close. Is my thought.

Pertaining to Dr. Brand and Coop.
Dr. Brand is probably slightly out of sync with Coop after their separation so she is probably a little older than she was, then he is... << if that makes sense. Also, there wouldn't have been a rescue sent out for her yet. Because she would have just setup her beacon, the time dilation effect would have meant some 90 or so years later from when Coop and the gang took off they might have gotten a signal thru the wormhole. But after the wormhole closed then it would have taken even longer for the signal to reach them. Because they would lose their window to the other system.

Pertaining to Coop finding Brand
OK, so this is a lot of speculation. BUT there is a slight possibility that when the wormhole was swinging around that we could see recognizable constellations and are able to get an "idea" of where this place was. So he might have some clue as to where she is in the universe... BUT that doesn't matter... I mean even if he was able to trace her to a single galaxy.. It would still be like looking for a needle in a stack of needles (where the needle stack is the size of the mass of earth... or something... probably worse). IF we solved the equations for gravity and were able to lift off from earth, then maybe we can warp the space around a small ship like Coop left in to travel faster than light IF they have an enormous energy supply to feed it. Then if he could possibly go fast enough maybe...I'm pretty sure he'd never find her... But, another idea in the movie was that love transcended space/time...so maybe he could track her using love???? **love-dar**?