Yes. The "Add to speed dial" command is gone now. This was an intentional change. See "DNA-100556 Confusing Cmd/Ctrl+B behavior in https://blogs.opera.com/desktop/changelog-for-90/. You must use ctrl + d now and pick the speed dial folder explicitly (if it's not already selected). Then, hit ESC to get rid of the dialog. If the speed dial folder isn't already selected, you'll have to use the mouse as the folder drop-down isn't keyboard accessible (long-time problem).
You can add ctrl + b as an additional option to the "add to bookmarks" command at the URL opera://settings/keyboardShortcuts if you like. You'll just still see the dialog and have to hit ESC to close it.