When will Apple release a screenless fitness or longevity tracker band?

Unknown Apple does not disclose future plans ahead of time, and users in this user to user forum, do not have access to Apple's internal development plans.

If they ever plan on releasing a band it will be announced the same way they announce other products.

these forums are user helping other users like yourself, it's sort of going to a physical apple store and asking other customers their advice

if they have plans they do not disclosure it with us, and if they did to individualsm then I would assume said people would be under some nondisclosure agreement which would get them into trouble spilling the beans to you.