It's interesting to see outsider perspectives on Shantae's Smash chances, because you see those that pay attention and those that don't. In one video I recently watched someone said Shantae didn't have much of a chance because she's not as popular as other indies like Shovel Knight, Undertale, and Hollow Knight. In another they said Shantae had good chances because Wayforward and Nintendo have been working together for a while.
I think the outsider perspective is interesting especially because it reaffirms just how special of a push it would be for the Shantae IP should she get into Smash. Shantae honestly is popular, but the opinion on the series itself varies widely. Some say it's an enjoyable platformer with funny writing, and others say it's mediocre and stale. That mixed viewpoint can lead people to not want to try the series, especially considering it has five games. Introducing people to it via Smash will reaffirm that Nintendo not only has confidence in Wayforward, but the Shantae series as well. On top of that, Wayforward is trying to establish itself over in Japan. Japan usually doesn't receive western indie games that well, but there may be an exception if Nintendo vouches for it. Anyways, it'll be exciting to see what happens.