Unfortunately, no. There is no tool to got directly from Photos to LR.
Well that is bad luck. Go figure.
I Made a mistake.
Any chance they will come up with migration tool for this?
Unlikely. The conversion should have left your library in place, but post aperture-to-photos images will not be captured in Aperture. I'd either use your old library for the conversion and manually export and import the new images, or restore from backup.
From the Lightroom File Menu:
File > PlugIn Extras... > Import from iPhoto Library.
It works just the same with Photos.
this box stayed up for about a minute with nothing seeming to happen. Wait.
Note: The "From Photos folder is one I created. I had to ask to show parent folder a couple of times before it showed up. The rest of the structure is just as its stored in Photos.
Very nice! Wonder if Apple left an Aperture metadata stub in the photos library, or if Adobe updated their Plug-in.
Oops. My error.
I was distracted while testing and didn't realize it was pulling from my iPhoto Library and not the Photos Library.
What I do know is pulling images from the Photos Library is as easy as creating an alias of the Masters folder (inside package contents). Put that alias wherever you want and then Lightroom can import the images.
Just the images. Not ratings and colors.