Else:
As I reported the type was correctly reported as raid member upon (re)setting the array up (while it was mounted). But on one of the subsequent reboots things got changed around, and then blkid reported luks type (while it was mounted as such). Maybe some other part involved is the cause? What identifies the UUID in initramfs for cryptsetup to open on boot?
Can you confirm the behavior for 2.16-1ubuntu5?
Else:
As I reported the type was correctly reported as raid member upon (re)setting the array up (while it was mounted). But on one of the subsequent reboots things got changed around, and then blkid reported luks type (while it was mounted as such). Maybe some other part involved is the cause? What identifies the UUID in initramfs for cryptsetup to open on boot?