An update on this, as someone just re-tweeted this post from 2017: despite good progress elsewhere in the borough (e.g. Haverstock Hill), the Delancey-Pratt link is still missing, and trying to connect from CW6 to the Primrose Hill LCN route is still nasty, or very indirect.
Camden Council has again taken no decision on the Delancey-Pratt cycle link, because of a group of local objectors. Safe cycling on our streets should be a basic right, not something that can be blocked by groups of NIMBYS for reasons of their own prejudice or even convenience.