Ever heard of the term “Double Orphan”?
Sounds weird, doesn’t it?
Actually, this is the valid term for children who have lost both of their parents, no matter which way, so including through disappearance of parents, and abandonment.
Still, it ain’t that weird that you might not have heard about it.
Most use the term Orphan already incorrectly…

While the term “Double Orphan” leads back to the United Nations, just like “Maternal Orphan” and “Paternal Orphan”, which are when only 1 parent is lost.
The term “Orphan” is in dictionaries something quite differently, and therefore were all the problems are.
The term “Orphan” in dictionaries remains having the (stigmatized) meaning of “a child whose parents both died”.
Simply put, when it comes to dictionaries, a lot of children have no term describing them because they only lost 1 parent through dead, or have lost 1 or both parents without them actually being death.

Yet, it is not even done at just that.
When we look at the term “Orphanage”, it is mostly in dictionaries as “a home for children whose parents are dead or unable to care for them”
While the meaning is actually not that clear, which at a dictionary it should be, it is not correct when we look at the usage at most of the world.
Which is where the United States changed things, and possibly more “English countries”, by using the word “children’s home”, which unlike an orphanage, is a place where all children could come to live, without the need of having lost both parents, or by general usage, without the need of being an orphan.
In fact, most interestingly, orphanages do not officially even exist at the USA (any more), they are all children’s homes by now.
The term “Orphanage” is instead often (incorrectly) used for children’s homes.

Yet, I can not understand how hard people actually make this…
Basically the only changes needed is that the term “Orphan” comes to mean “A child who has lost 1 or both parents.”, and the term “Orphanage” to become “A home for children without parental care”, or, in case you want the term “children’s home” to remain, “A home for orphans”.
It is kind of sad that it is so hard to get dictionaries changed, while most already use the terms in the way I suggested…