I have no doubt that your cats would miss you. Pets become really attached to their human families. If you were to leave them, they would mourn you.
However, you've already done the first thing you can do to make it easier for them: you've adopted two kittens. They have a bond with you, but they also have a bond with each other. I imagine you have considered arrangements for their care in case anything happens to you, like a hospital stay or protracted illness. I would also take steps to see that, in the event they must be rehomed, that they are allowed to remain together, at least for the initial adjustment period. In our church, when a person with pets passes away, congregation members do make an effort to make it as easy for their furbabies as possible.
You can do a few things to make your cats more attractive to potential adopters, like making sure they are spayed or neutered, have regular visits to the vet, eat healthy food, and are thoroughly housetrained. Keep a file on them in with your other important papers that records their names, date of birth (or approximate