No surprise they want the big one to operate the MAD, especially with the IB codeshare in full swing. Also the E190 is not weight restricted on the MAD, unlike the E170 can be sometimes.
Nothing on the new route(s). It was mentioned a while ago they were looking at more leisure destinations. But I wouldn't put my money on it.
The question is; can the E190 do the 1050nm to HEL with a good payload all year round? It's only 200nm further than CPH and that's no issue. Add a codeshare with AY to the mix and who knows.
*Note - pure speculation on my part. It just seems BA is very Scandinavia focussed lately.*