I can only speak from my personal experience with this.
I had bought an adult mating pair~ In the beginning the male was very outgoing and tame while the female was slightly cautious. I had them for years and the male *never* fully
bonded with me, he was
bonded with the female. I think he was so tame because he was
bonded already~ and when he realized my home was his new home he became a bit withdrawn. Now the female~
bonded completely with me (and she was the less tame, more wild of the pair). These two were incredible~ And his
bond to her was so strong that he couldn't have survived a separation. At one time she got loose (she was very mischievious~ lol) and was lost for 2 days. He became so depressed I thought he was going to die, he curled up and looked at me with the saddest eyes I have ever seen~ and luckily we found her that night because I don't think he would have gotten up again!
Anyways~ when he died of old age, she died a week later. So I guess she needed him as much as he needed her.
I recently had one of my suggies die and his cagemate is very sad~ In this case there is nothing that can be done about the separation~ So we will see if he can live without his buddy~
I supose it really depends on the Glider in question. Some depend on each other much more than others do~
My remaining glider seems sad but I think he is doing much better than I had witnessed with my first pair.
So I suppose it may matter whether they have to be alone after separation, how big the colony was or if they were just a pair.. and if being re-homed whether they were just carted off to a new home or if introductions were slowly made with their new owner/family.
I also know someone with the exact opposite of my issue. One of his suggies died and the twin never missed a step and is still very happy and well to this day. (They never even got him a new buddy!~ which I would have never had the guts to risk keeping him alone all these years~ and still wouldn't suggest to anyone).
I also think in captivity there is less competition than in the wild so stronger
bonds can be formed.