I misunderstood you, I thought you were questioning the subject of the news story. Although this particular article only used "ethnic cleansing" as a description of what the secular state of Israel is doing to Palestinians in Gaza you are correct to say the article assumes the reader is already aware of the ethnic cleansing occurring in Gaza and doesn't make that specific argument here.

If you are interested in why it is accurate to describe the actions of the Likud-lead state of Israel against Palestinian civilians as ethnic cleansing, this application for court proceedings does an excellent job establishing the legal case for genocide including support for the claim of ethnic cleansing. Legally, in a preliminary ruling the International Court of Justice has found that the charge of genocide is plausible and the case will move forward.