After almost 3 years after the initial version, route blinding has been added to the Lightning specification.Route blinding allows a recipient to provide a blinded route to potential payers, thus improving receiver privacy.This is an alternative to rendezvous to preserve recipient anonymity and has a different set of trade-offs: Onions are re-usable, but the privacy guarantees are a bit weaker and require more work (e.g. when handling errors).
Here’s a quick route blinding breakdown and development status update by @niftynei: