Not ever seeing these emails, it depends on where you stand. I can see how it would benefit the organization to have people know what is being shipped in other areas of the org, and also provide valuable feedback loops from differing perspectives.
However if all the threads are just “great job on X!” I can see how that could be low-value self promotion.
However if all the threads are just “great job on X!” I can see how that could be low-value self promotion.