I was just replying to your post, but it looks like you removed the linked article (I was going to mention that though it does describe how soldiers and civilians are using the latest consumer technology in Ukraine, it specifically doesn't mention photojournalists).A military photographer I know used cellphones and his cameras to photograph the war in Iraq. Yes, that was several years ago, but I have no doubts that cellphones are becoming quite useful at the war front.
As I said earlier, most photojournalists in Ukraine use cell phones to communicate and to capture video clips that are used on occasion. Definitely useful. And while I'm sure some use them to take photos for publication as well, from what I've seen while checking metadata, phones aren't really what is being used by professionals. On occasion there are "UGC" images that were crowdsourced and moved to the wires. Those are, by far, in a very slim minority of images.
EDIT: Added "in Ukraine" for clarity on what photojournalists I'm discussing.