As a language teacher using canvas there are a couple of aspects of the Classic quizzes that I will greatly miss.
1. Multiple dropdown questions: I use video, audio, images and texts frequently with my students. I love the multiple dropdown questions because they allow me to put the questions relating to that specific source together in one place, with the prompt. I do not have to put a 2 Minute audio in each individual question. the suggestion of Fill in the blank for these questions, doesn't work for my class, as the questions are typically different features tied to the source.
2. record: In classic quizzes, students can record audio in the RCE. That is great for me, because I can set up oral assessments, in which students listen to a prompt I post, then they respond, and work through it. It flows well as an interview or a simulated conversation. That functions better than the assignments and external tools like flipgrid. New quizzes has abandoned the record feature in the essay questions, and for me is a downgrade from classic quizzes.
If canvas brought these features back in to the New quizzes, it would be a lot better tool for my class, and I am certain for other language classes too.
When I imported my multiple dropdown questions from old quizzes to new quizzes, I discovered that dropdowns are an option buried within fill-in-the-blank questions of new quizzes. You will be able to continue using those questions. Just type the complete statement and then highlight the portion for a dropdown and select create blank space. There does not appear to be a limit on the number of blanks that may be created this way. New options will appear for answer types, and one of those is dropdown. (Another related option is a bank of answers. The banks of multiple bank answer blanks are merged in the student view into one bank that students can mis-match into any blank.)
I don't accept audio responses, but the RTE is an option that is turned on by default for essay questions, and it does allow students to upload media (including audio) that they have already recorded. It is not quite the same as having the record function built into the quiz, but most computers have a voice recorder app as a part of the operating system. It should be possible to adapt the instructions from those questions, as long as the quiz is not using proctoring programs that block other apps.
A problem with going to another app for recording, is that it is requiring students to have to do more (tech work) to do something that was wonderfully streamlined. We don't currently have proctoring programs, but were looking in to it. I do review the activity logs, and students are not supposed to navigate away, while taking assessments. Test are not accepted if they do, but they would have to in this case.
I will try migrating a quiz with the Multiple Drop down. and check options you mentioned, but often there are questions like: what is the purpose? Who would be most interested? How could (...) be expressed differently? and those don't lend themselves to fill in the blank.
I agree that navigating away from the quiz is a serious problem for exams. For now, the audio upload might be your best alternative, but there is a related open idea conversation you might join to request the added feature: https://community.canvaslms.com/t5/Idea-Conversations/New-Quizzes-new-question-type-Audio-recording/...
I think a key problem with categorization, dropdown, and some other question types is that the choices are not compatible with the rich text editor. If those could be made so that rich text is a possibility then this would be a huge help and upgrade from Classic Quizzes.