Besides the reasons given by you,in fact Astra 1N is provisional, as we all know, on this position.And this for four reasons,two technical,one commercial and one strategic: 1.once he is a backup satellite,and 2.on the other hand it saved energy using for feeds.In two years Astra 1N 3 should be operating at full capacity when it will be moved to 19.2 position.
3.From the commercially point of view,as the two-year as sit on this position, amortized costs in good part.
4.And there is another very important reason:Astra fleet is hardly used for the transmission of feeds,most are provided by others satellite operators:Eutelsat,Intelsat,etc.Perhaps it will attract many TV operators,that customers will migrate to the Astra.As we have seen today with Arqiva and Globecast,Eutelsat's old customers.