In November 2018, Beck posted two short clips on his Instagram of his father conducting a string section, while a tape of Beck's voice sings some new song for them to play over. The above lyrics are what I could make out.
A day later, Beck posted a photo of sheet music to instagram, showing the title of a song called "Roma." It says at the top "arranged by Beck Hansen" and "Orchestra by David Campbell." Beck's caption for the photo explained that he was "recording orchestrations for the film Roma by Alfonso Cuaron."
The song and orchestrations are not in the film Roma, which came out on Netflix in December 2018.
However, it appears that at least one artist is releasing an "inspired by Roma" single in January 2019, so I would assume that Beck will be too. (Nothing officially announced as of yet.)
To clarify: Beck shared two things - one clip of him singing over an orchestra, and one picture of sheet music for "orchestrations" titled "Roma." It is possible they are the same song, or that there are multiple songs/tracks in play here.