Edit: please pay attention to the first two words of this headline. We don't actually know if Trump received a target letter, he could be lying out of his ass to mess with the investigation.
Newsworthy because this means an indictment decision is near. We already knew he was a potential person of interest, that is why the Special Counsel got appointed in the first place.
No, newsworthy because Trump is using his public profile to mess with this investigation again. We have no way of knowing whether or not he actually received a target letter because he lies about things constantly and could be lying about this as well.
I have a pet theory that he knows it’s in the future but not as imminent as he suggests (like the docs case) but if he says it’s imminent now he can spin yarns about their case being in tatters and delays being due to mistakes, etc like he tried to spin for the docs case.
I just don't see a real motive for that 3D chess move stuff. Last time he said he got a target letter it was because he did, and he got indicted a week or two later. Simplest explanation is that he's trying to deflate the power of the coming indictment by making it no longer a surprise.
Personally I'd be shocked if he lied about something that made him look so bad from every angle. There's no rhetorical advantage he gets from being indicted 3 times that he wouldn't get from 2. You're saying it would "mess with the investigation" but the people directly involved in the investigation are exactly the people who know the truth of the matter, it's the public he's interfacing with here.