I have a hard time accepting the notion of a US flag that commemorates the loss of states via secession or even union of different states. I think if that ever came to pass, only two options would be considered: (1) a law mandating retention of the exisiting flag (50 stars/13 stripes if that happened today) as the unchanging national flag only unless new states are added, or (2) a law designating the original 13-star/13 stripe flag in one form or another as the never-changing US flag no matter how many states there are.