Hello and welcome to the forum! They used to show their upcoming releases on their website, but it changed a little while ago and I don’t see it there anymore. Not that they did the best job of keeping it up to date anyway. 

Maybe @BriarBerg may know the release schedule?

I have a little bit of insight into this—there seems to be a tentative schedule. 

Each of the C&D Small Batches seems to have a rough time of year for release, if they are released at all that year. Some of the most celebrated are annual, such as Carolina Red Flake (though whether or not with Perique varies) and Sunbear. Red Flake is usually released around September/October, Sunbear around July/Aug. Others may not have a release every year, 8 State Burley was released in March 2022 and May 2021.  

This is just from my own observation of the trends, so nothing solid, but there's some room for prediction.

If you want to make sure you seem them before they drop, Cornell & Diehl's instagram is probably the best place. 

They are also more active on Youtube than ever