Well there are several explanations as there are several Wilsons! The 'real' Wilson Commandoes i'm not certain even featured in Meerkat Manor (he might have appeared briefly but not as a cameo). The Wilson featured in Season 3 was played by atleast 2 males (probably more) Drew Commandoes and Tonker Vivian. The Wilson for season 4 was mainly portrayed by Homestar Runner of the Young Ones Mob.
Very few of the members shown on season 4 are even still alive. I think whos left are Monkulus, Flo, Billy, Ella, Nugget, Juno, Marico, Oriole, Sabota, Axel, Rufus, Zaphod and Hawkeye.
The story of Mozart and Wilson was a love story much like Romeo and Juliet. There is no factual documentation of such a rover with Mozart. It is very hard to say what happened to her while she was alone for a few weeks.
What the storyline shows us is the desparation of both Mozart and Wilson to start a new life, a new family.
The call of the family is very strong in meerkats, even perhaps stronger than the will to survive, hence many meerkats give their lives so that the family will continue. Flower was the shining example of this and so was Shakespeare and Simon.
Though the stories are not spot on they are true. Many meerkats die trying to start a new family and many die so that the rest of their family will be safe.
However they decided to show Mozart's passing, it did give us closer. I would have hoped that she was not alone for too long. That maybe a "wilson" appeared for her in her final days. The memory of her is so strong but sometimes shadowed by her laying on the ground which is not how she was actually found at all. She really touched so many of our hearts with her kindness and gentleness. I felt for her when she would get pregnant, get evicted and be alone struggling to save her pups. R.I.P. Little Mozart!!!!