I just converted a legacy page to the new editor.
In this page I had a lot of codeblocks that are "optional": when the page opens they appear reduced and you must click "Expand" to see the whole content. That is very important, because these textblocks are very long. Without this function, users are forced to scroll very much and the page looks very confusing.
The converted page no longer supports this "optionality" of codeblocks.
Thus, I am now looking at endless codeblocks :-(.
It really would be best if the "expand"-option for codeblocks was not depreceated. Actually, I really wonder, what drove you to take away from us this really important feature!
As it stands now, I have a lot of work: I must create an "Expansion" for each of my codeblocks and copy the codeblock into that. And I must do this on many pages (> 20).
I'd really appreciate Atlassian to not cause this immense extra work!