I plan to remove our partial implementation of -webkit-hyphens. Currently, blink implements 'none' and 'manual' values of -webkit-hyphens, but does not implement 'auto'.
Only implementing part of the CSS property makes it hard to feature detect blink's support of this feature.  There is some partial work done for implementing 'auto', but no one is currently working on this feature and it is adding code complexity and bloat since we compile in a third party hyphenation library.
The only visible change is that "-webkit-hyphens: none" will no longer work, but I suspect this is not used. You would need to manually add ­ markers to your HTML and add this CSS value to not break at those places.
Support for this feature is almost complete, but I have been unable to find anyone interested in owning and maintaining the server components which provide the dictionaries. We should remove the code until we can find someone willing to own and finish the feature.