Hi @jeffmccauley, @wgk333 and @allezBrown, thank you for sharing your concerns here.
First to clarify, Search Timeline widgets will be deprecated on July 27, 2018. They will fall back to a simple link that points to the corresponding search results on twitter.com. And we don’t have any plans to support embedding hashtag Timeline widgets in publish.twitter.com.
However, we are continuing to support collection, profile, list and likes Timeline widgets. Would any of these embed options suit your use cases where you are using a Search Timeline? Once you have a collection (see Curate a Collection of Tweets using TweetDeck or API), profile, list (see How to use Twitter lists), or likes (associated with a certain Twitter account), you can grab the code snippet to embed them using publish.twitter.com.
If not, I would recommend that you consider using the RESTful Search API which is a bit more involved in terms of implementation. In other words, it’s not as simple as copying and pasting embed code from publish.twitter.com; but it gives you the most control over how Tweets are rendered.
We did not come to the deprecation decision lightly. As a matter of fact, over the past few years while we actively supported Search Timeline widgets, we observed low usage of Search Timeline widgets compared to other types of Timelines (collection, profile, list and likes), and rather high engineering cost given the net benefits they offer to developers and end users. By deprecating widget settings and Search Timeline widgets, we hope to focus better on improving existing embed options and investing new ones to keep up with your evolving use cases.
Hope this helps!