It doesn't seem like anyone would know what a supposed product might potentially support or not support.will the upcoming new apple lightning headphones be backward compatible with iphone 5/5c/5s/6/6s/5se?
I think they will make it work with the 5-6s, but there may be a really small chance that they include a feature on the headphones that only works with the 7.Lightning headphones work with lightning ports, so there is no good reason they wouldn't work with the 5-6s. The only plausible possibility is if Apple makes them incompatible on purpose to promote the 7.
Heart rate sensor built into lightning headphones would be a good addition to HealthKit ecosystem.I think they will make it work with the 5-6s, but there may be a really small chance that they include a feature on the headphones that only works with the 7.