That was the original agreement between SCR and SWR, but there seem to be some problems now with demands for extension to Latur. That will have to be sorted out before any progress is made.
BIDR becoming a dumping yard is unlikely. MTM-SC was extended only because it was being shunted till VKB everyday for parking, and has a rather early arrival and late departure at SC. Only 2 other possibilities are MAS-HYB, Janmabhoomi (again, just a possibility) which will not require any maintenance (and Janmabhoomi 'may' replace SC-BIDR express if extended at all).