I think it's a misconception that the E195 would be payload restricted at SEN.
I believe this stems from the fact that the TODR of the E195AR (Additional Range) is 2,179m whereas the Flybe E195LR has a TODR of 1,880m at MTOW. It's TODR for 500nm, full pax, ISA, SL is 1,432m so a range well beyond that should be possible from SEN's 1,799m TODA. There might be rare instances of restrictions with temperatures well above ISA and runway 23 departures but no more than with the A319 currently.
It will surprise me if the E195 is be the aircraft used as Flybe's fleet of nine aircraft looks to be fully committed at present and I assume this will continue to be the case through 2017. It would however be an appropriate choice of aircraft if available in my opinion.