Adobe Lightroom CC is now available on the Mac App Store. To answer the first question users will have, the answer is no, Lightroom CC Classic is not available, only the new CC version.
Lightroom 4 was available in the past, but that changed with the movement towards the cloud. This approach for Adobe should yield more subscriptions through the Mac Store and and for the first time make it more widely accessible. Mac users could use it before, but this will put it front and center with Photoshop Elements app in the store.
They are offering a 7-day trial and managing it through the store handles updates and renewals via the store if that’s a preference. After a 7-day trial, then you’ll need to buy a subscription for $9.95 per month or $118.99 per year. The subscription comes with 1TB of cloud storage. By signing up through the store, the billing will be charged to your iTunes account automatically.