It looks like the work is still underway, with another pull landing just last week. Doug seems to be aiming for the Swift 6.1 release, as those prebuilt library pulls now only go into the release/6.1 branch, not even pushing them to trunk yet.
I'm sure they'll let you know once they have it working for you to try out, as unlike previously, you can see there is work on this ongoing in the OSS SwiftPM repo, though obviously nobody is guaranteeing any deliverable or release date yet.