We should not forget that MST was a makeshift route launch when CGN became unfeasible because of Ryanair launchning STN-CGN. If MST was expected to have great potential, it would have been among the first six routes announced.
As for ANR, it was the most non-sensical route given the 20 year long tradition of VLM/Cityjet on ANR-LCY, offering the better frequency and better London gateway.
The more interesting question for me is if there are other potential destinations for a 70seater turboprop from SEN to which the freed up capacity could be deployed? It would probably need to be an airport with no current London link, particularly no STN or LCY service. The only airports I can think of are EBJ, SCN, PAD/KSF, LGG