Hi @Alsee. Sorry for the confusion. The short version is that our long term plan is to do what you suggest.
The longer version:
While the zero results rate is an easy indicator to compute, we do recognize that it is low resolution and of limited value. A big swing up or down is a cause for concern—so it's a good metric to track on the dashboards—but getting it to zero is no longer a goal. One of my earliest write-ups covers lots of cases that do, in fact, deserve no results (the write up itself is a bit of a mess—sorry).
Mikhail's Zero to Hero analysis, which Deb linked to in the email, highlights the text characteristics that are most often associated with zero results. While zero results may be appropriate, a very high failure rate points to places where we could possibly make improvement.
An area that I'd identified earlier in my research was queries in the wrong language, so now we run language detection on poorly performing queries for some wikipedias and search other more appropriate wikipedias. As an example, a search in Russian on English Wikipedia can show results from Russian Wikipedia.
Two areas that Mikhail's report found as potentially high-impact (both relatively common and relatively unsuccessful query types) were queries with question marks and queries with quotation marks. I did a quick analysis of both and found that they did look promising. This led to a more thorough analysis of dropping question marks, and eventually a change in the question mark syntax that makes naive use of question marks behave as a naive searcher would expect.
Quotes are harder, because as you point out, the query you intend (with quotes) and the modified query (without quotes) are not the same query. We would of course want to show the "before" and "after" like we do with "Did You Mean" queries, and cross-wiki searches based on language detection (as above).
The actual implementation of quote removal is complicated by the fact that it could interact with Did You Mean, language detection, sister-wiki results (as discussed in Deb's email), the modified question mark syntax, and other forms of "second chance" searches we might implement in the future. We have an outline of the problem and the beginning of a discussion of how to deal with it, but it's not high on the priority list right now.
So, to sum up, what Deb was referring to in her email was the idea of automatically/"by default" taking poorly-performing queries that have quotes and re-processing them without the quotes, rather than relying on the user do it, if they choose to and they realize that it could help. The UI for such a process would include the before and after versions, as you suggest. Again, sorry for the confusion.