At release level, there's a certain appeal in being able to push the big "go" button, and run "everything".
If i index my objects in the right way, this is theoretically possible (if we ignore minor issues like pre/postload approval or foreign keys, but meh - details...) It's a client request, not my idea specifically.
However, the ability to have the datasets listed in a specifc sequence, and that sequence to NOT be editiable except by admin role has merit.
It would be possible to align the datasets into a runbook order, or group like objects etc. The runbook order has particular visual appeal - it's letting someone be on the system and validate status at a glance within release ETL.
I know it's perfectly possible to do it now - just spend 20 minutes dragging & dropping, and I'm there. But you can guarantee that with 10 developers working on objects, and the dataset index also being the release index, by tomorrow morning, my sequence has gone.
That's human nature - I order my datasets to group them while I'm working as a developer - I'm not looking at the "bigger picture" the PM wants.
I don't know whether it's easier to add a second index key that only shows at release level, or to remove access to changing index by the developer role (but hopefully still allow drag & drop while working?) The overall idea is that I can have a list of datasets on display in Release>ETL that shows only in my desired order. If my order matches my runbook, it's easy, visual validation for everyone.
The idea is not that this is possible, it's the request that it become 'locked' to prevent developer changes.
All this said - it's very much a "nice to have" and not "essential".