How does it matter? That someone wanted to have kids doesn't mean that he want's them under the same roof till the end of his life. Especially with the grandkids. People should not be taking for granted that they can simply come back to their parents, or close to them and ask the to look after the kids. In the world where retirement age is increased more and more, people deserve also "me time". If grandparents really want it and ask for it, then great for both.

Writing this as parent, having small toddler, leaving abroad, far from both mine and wife's parents. It is harder without support, but manageable.