These are not Keto. Black edamame is another name for soy beans. Soy, in any form, is inflammatory and should be avoided on a keto diet. Just another company trying to cash in on keto.
Have a source? I’m not Keto, but was curious and google comes back with mixed results. Seems, yes black/green edamame should be avoided, but can be used in moderation as a replacement for traditional beans in order to get some fiber. I guess it depends on how far Keto you have gone.