Again, anything is still possible since all are stabbing in the dark with no map.
Sakurai and Nintendo do want to keep everything a secret until the time is right to show. Like that unexpected news about Smash Ultimate Update 3.0 and Joker's layout of his moveset.
Plus, we got Shantae 5 (not official title) coming soon. So we have something to fill the gap in case things doesn't fall in the right place.
Also, lets try to avoid being narrow-minded until the big news arrives for the new challenger(s).
Mod Edit: Second Image removed due to uncensored swearing. Please censor the words in the image first before posting.