oawk should go ... go ... go ...

Yes, there could be someone still using this ancient steaming pile. But mostly the old awk is a barrier to adoption. It would be better to be compliant with newer standards by default.

One possible difference; nawk is reputed to be CSI safe, whereas XPG4 awk isn't. Anyway, we have 2 too many awk implementations. Elimination of the eldest is a step in the right direction.