We are excited by the new tools in Quizzes Next, but they should not come at the expense of eliminating support for the use of other third party content editor plugins such as Kaltura, Google, Box, etc.
Quizzes Next is an LTI tool. Because of this, LTI tools installed in the "regular" Canvas rich text editor, like the Kaltura embed media button, Google, Box, etc., are not available.
This is a serious loss of functionality, especially for those of use who rely on external tools in quizzes. We know that the LTI spec supports the nesting of tools (nesting the Kaltura tool in the Quizzes Next LTI, for example).
There is an insert media button in Quizzes Next RCE, but inserting embed code other than YouTube or Vimeo results in the code being stripped on save (I've reported this as a bug and it is being investigated).
Even if all iframe embeds worked as expected in this tool, the quiz designer should not have to go to herculean efforts to obtain media embed code external to the quiz development process that is available with the click of a button in the regular Canvas text editor.