Slade left his job having done absolutely nothing to further the career of the young players he inherited when he took over at Cardiff. The release of Yorwerth was symptomatic of this problem which existed throughout Slade's tenure. It looks like Yorwerth may not have made it at Cardiff (although that shouldn't be taken for granted just because he was released by another Championship club from the other side of the country), but, like, so many other Academy products of a certain age, it would have been good to have seen him given an occasional chance to show what he could do in the senior team in the way that so many similar type players were by previous City managers.
Anyway, best of luck to Yorwerth at Crawley.