If it is, it hasn't made the BBC website yet, which is usually pretty ahead of these things. Oh dear!
I can't find it reported anywhere else either, so if this was a press release as the article claims, then the news would be shouted from the roof tops by now - and the article is timed at 18 hours ago. Also why would he announce this in the middle of a tournament? Check the news out if you want to (this has always been my source) - https://www.newsnow.co.uk/h/Sport/Tennis/ATP+Players/Andy+Murray
Anyway, after reading it, I'm convinced this is old news which is being dredged up because Andy has made similar comments in the past. but that's going back about 3 years. Also the article has got his ranking wrong. He's currently No. 40, not No. 44. And nor has he been 'struggling with injuries' for quite a while now.