They appear to be perfectly valid as they are. If you don't need to cancel them, there's no need to mess with them.
In fact, you can even use the new feature on them to modify them now without cancelling them, if you decide you do need to change parks. You just have to do them individually rather than as a group.
Not having an annual pass or anything of the sort, I can't talk to all the advantages of the new system. But I do appreciate the following three changes so far:
It's much easier to select my travel group from amongst all my friends and family, as it grouped all the people with the same tickets. (This might not work for everybody, but can't imagine it being more confusing than the way it used to be.)
I no longer have to scroll through the whole calendar to find the dates of my visit. It defaults now to the dates of your ticket/stay if they're dated. (If they're open dated, though, it still defaults to today's date.)
I don't have to cancel the reservation to change the park or date. That would have been very helpful last night.
Among things I'm not a fan of is the fact that it emails confirmations now, so I've been spammed with over 60 reservation updates.