For the record, as we wrote in the MR, we discussed also on IRC and we decided of merging !643 (merged) because suggestions are disabled by default both on PBM (Firefox's default) and in normal mode (we set browser.search.suggest.enabled to false), and at the moment many other search engines still have the suggestion URL.
However, we're still not fan of this search suggestions, and we will keep it off by default.
It sounds like we've resolved the original issue, and enabling search suggestions in private windows is a bigger topic. However fwiw I wouldn't consider search suggestions to necessarily be a dark pattern. In many instances they're a good, time-saving feature.
A lot of it comes down to how much we trust the search engine provider to respect the user's privacy. If we were to be ultra conservative with the search engines we bundle in #41835 (closed), I wouldn't be averse to finding a way to enable search engine suggestions in Tor Browser that doesn't involve turning PBM off.
There's a preference to turn on suggestions for PBM, too.
However, keep in mind that it's something that Moz does by default, at the moment, and I'd like to explicitly add it to our profile, until we decide that maybe we can turn them on.
However, this is the big point:
A lot of it comes down to how much we trust the search engine provider to respect the user's privacy.
+1 for being something that is a bigger topic (indeed, I consider this part of the review to our choices, and the creation of an updated design document).
There's a preference to turn on suggestions for PBM, too.
However, keep in mind that it's something that Moz does by default, at the moment, and I'd like to explicitly add it to our profile, until we decide that maybe we can turn them on.
Okay that's good to know, thanks.
Also, users might add new search engines by themselves, like adding new extensions.
Great point. If we were to enable search suggestions by default, we may want to apply some custom UX to review this preferences as a second step (with appropriate warnings about privacy) when users add new extensions.