It appears to have an unclear lifespan. While it has been fully replaced by the Feed Dialog, it's still working now and is used all over the internet. I can see the case where it won't see any further development or features, but it's a tough call whether or not to incorporate the deprecated method or accept possible risks of the current methods - Like button or Feed Dialog.
The bug you referenced is from over a year ago and in fact the feature is no longer deprecated. The documentation page [1] used to highlight the deprecated status but has recently been updated and any mentions of deprecation have been removed.
Interesting, thanks for the link. When I implemented a share in an app recently, this wasn't an option. I wish there was more version information on the page. The only reference to a timestamp now is that this page was updated a week ago.
You can fairly easily use /dialog/feed "manually" instead of sharer.php if you're worried about the latter's lifespan – you just need to set up an app for your domain first since "app_id" is a required param (and also "next", which is a redirect URI on the same domain).
Example: http://antiprism.eu/en#share
It appears to have an unclear lifespan. While it has been fully replaced by the Feed Dialog, it's still working now and is used all over the internet. I can see the case where it won't see any further development or features, but it's a tough call whether or not to incorporate the deprecated method or accept possible risks of the current methods - Like button or Feed Dialog.