Afid, I have a Phalaenopsis mannii that bloomed last year and developed a seed pod. I have been growing my orchids inside under lights since the '80s and have never had a plant out of the blue develop a pod like this. I assume it got selfed somehow, but had 1-2 other plants also blooming at the time so am not completely certain. If you want the pod to experiment with I would be happy to send it to you-just PM me your address. I don't know how long it takes for pods to mature on P. mannii, but it has been on the plant since June 2019. Also don't know if there is any viable seed. Would be interesting to try and find out.
Susan