From 4 June 2017, the Brussels Airlines Avro RJ100 will be replaced by the Cityjet Sukhoi Superjet on the route between Brussels Airport and Stockholm Bromma, as Luchtzak forum member Shengenzone discovered in the Brussels Airlines booking engine.
Stockholm Bromma, the largest Brussels Airlines Avro RJ100 destination, cannot be served by A320 family aircraft because of local regulations driven by environmental concerns. It will thus become a Sukhoi destination. The SSJ100 has only recently been approved for that aerodrome.
Forum discussion: http://www.luchtzak.be/forums/viewtopic.php?f=7&t=42627&start=2740