BBD has launched what amounts to a CR7 conversion to a lower-MTOW 50-seater. Sounds useless except for real-world US regionals (scope clauses) but here it is:
https://www.flightglobal.com/news/articles/bombardier-pitches-crj550-as-solution-to-700-aging-455575/
https://www.bombardier.com/en/media/newsList/details.bca-20180206-bombardier-launches-new-innovative-50-seater-aircra.bombardiercom.html