This thread is more about how to make old files working in new system (manual convert to new node groups made out of field nodes, or auto convert to no hardcoded node tree), the old nodes would not be kept around either ways so I think we are fine regarding that.
The hardcoded store attribute node and extract attribute node though, I might be wrong but it sounds like they would be removed if we choose the auto convert option, which would also cost the devs more time and labor I think. Like a downside on both user and devs. So I think I like the manual node group more. Each node turn into a node group and done. Don’t know how hard it is, but it shouldn’t be that hard, I even made 3 node groups myself the other day:
(If it’s actually hard to do then I am sorry)