bmi Reg acquired 2 more E145s recently - G-RJXN in service now & 'XO now at ABZ being readied for service. Suppose not beyond the bounds of possibilities that they could acquire more, but I agree not all 145s will remain in the UK.
Re the DH8C, T3 had one on demo to them at HUY, which also appeared for a short time at ABZ (routed HUY-ABZ-HUY). So T3 may take one or two, WOW will probably take a couple as well I would think. Although T3 did say they were happy with what they had (JS41/SB20) & weren't looking for any "new" types. Things can change of course. T3 used to have E145s, but disposed of them in favour of the SB20, which IIRC suited T3 better - more fuel efficient for the routes they use/d them on. (Don't know why, I've never been a particular fan of the Saab...looks too much like an ATP to me!)