It has been proposed that raw string literals (preview) be dropped from JDK 12 (which enters Rampdown Phase One on December 13). Brian Goetz has written a detailed description of the motivations for dropping this preview feature (JEP 326). There is also discussion on this on the Java subreddit.
In Goetz's explanation for the proposal to remove raw string literals preview functionality from JDK 12, he writes, "The Preview Feature mechanism is intended for features for which there is a high confidence that the feature is 'done', and the likelihood that significant changes would be made before making the feature permanent is low." Goetz adds, "I am no longer convinced that we've yet got to the right set of tradeoffs between complexity and expressiveness, or that we've explored enough of the design space to be confident that the current design is the best we can do. By withdrawing, we can continue to refine the design, explore more options, and aim for a preview that actually meets the requirements of the Preview Feature process (JEP 12)."
Goetz also provides a sample of the feedback items they've received regarding raw string literals preview design and implementation. He concludes the message with the statement, "Discussion on the technical details of this feature can continue to take place on the amber-* lists" (amber-dev, amber-spec-comments, amber-spec-experts, and amber-spec-observers).