Are any other railroad than the LIRR considering to buy the DE30AC or the DM30AC?
I haven't heard of any. (I'm not an industry insider, so that doesn't mean TOO much, but I do keep my eye on published reports of locomotive doings.)
New Jersey Transit is getting EMD-engined passenger units of a different design. FRA rules for passenger locomotives have changed, so the ORIGINAL DE30AC or DM30AC designs would probably have to be modified anyway if more were to be built.