I might be in the minority opinion on this, but I don't think it should return if it's not going to be revamped. The way "Instant Tutoring" worked before is that a teacher would have to teach a minimum of 5 classes, before they could "request" that Instant Tutoring be activated. I felt that this was ridiculous. Just because a teacher teaches 5 classes, that does not mean they will be "teacher ready" and know what they are doing as a teacher.
If Italki ever brings it back, they should ONLY allow native speakers to have this Instant Tutoring option. Italki should go through an actual interview/assessment to ensure these teachers can speak the language sufficiently, and their education should be screened and verified. There are many English teachers on here who have no education and training, and this is a disservice to paying students.
Only qualified and reputable teachers should have the option of using Instant Tutoring, and Italki should be more selective about which kinds of teachers get this option activated.