Optimus, Elita, and Bee are not a family.
If you really think Optimus, Elita, and Bee are going to be a perfect, happy little family, WELL THEY ARE NOT!!! They're an incomplete family, a broken family!!! Because there's four members of their family, and one of them is lost! They're not going to move on from that, and be perfect, happy, or healthy, like he never existed. They're going to mourn him, miss him, be lost without him, it won't be the same without him. They're not going to be grateful-thankful with a limb clearly missing. They're going to want him back. They're incomplete without him.
The only reason people think are going to be a perfect, happy little family is because of the ending and its forced hope and optimism... and, perhaps, people's bais towards Megatron and the fact that they're so used to Optimus and Megatron being enemies, and the Autobots and Decepticons fighting.
But it feels like everyone's moved on and forgotten about Megatron/D-16, and that he was family too, and that they're actually a broken family. Foolishly believing they're a going to be a perfect, happy little family when they're the exact opposite.
It's not that I don't want them to be I happy, I do, I want all of them to be happy. But not like this. I don't want them to be happy. I want them to be real, to be genuine, to fall apart like anyone real in this situation would, to sit with their pain, and let out all their sadness, anger, and despair, validate the horror and hopelessness of their situation, to sit with their pain, and receive comfort.
Because Optimus, Elita, and Bee, without Megatron, are alone, and alone they are not complete, left for defeat, in need of a place to turn to. And to that extent, the Autobots and Decepticons are alone; alone they are not complete, left for defeat, in need of a place to turn to.