The inclusion of Pixelmator Pro is simply so they no longer have a hole in the software lineup as a competitor vs Affinity (I think the real competitor to this bundle) and Adobe
I think they view Photos as a viable replacement for Lightroom and equivalents.
That's probably a clue that maintaining Photomator is not on Apple's long-term roadmap. I imagine they'll merge some features into Photos and eventually discontinue it.
Photos would need a lot of work to rival Photomator.
If they're essentially shutting down Photomator development, after doing similar with Aperture many years ago, they do seem very determined to drive people to Lightroom....
I think they view Photos as a viable replacement for Lightroom and equivalents.