The term "Palestinian" to refer to the Arabs who were living here pre-1948, as well as their descendants, is a relatively recent invention. Here's another example showing this.
When the New York Times reported factually
The PLO's Bassem Sirhan wrote Palestinian children: "The generation of liberation" in 1970. One part stands out as a huge own goal.
There was a time the New York Times would never have dreamed of writing something like this
From the indispensable Palestinian Media Watch
A revealing and important read
I have to thank them for this
More proof there was no separate “palestinian” identity, and that the Arabs in the area considered themselves part of Syria.
Some more historical context you need to know about