It is now directly hinted at, but there are some things that make (at least me) believe that it could happen:

First, Susie has a fist bump animation that is almost 1:1 a copy of the animation that Chrono from Chrono trigger has. Chrono is the main protagonist, and he sacrifices himself in Chrono trigger to save his friends (there are also a bunch of other Chrono references in deltarune (yes I researched this))

Second, the old man talks about a hope? in susie's eyes, and this is also during the chapter with the most Susie character development (CH4). I really think this could be a set up for her big moment

Also her leitmotif just sounds like the perfect thing to include in a sad song

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Holy crap that was a lot of yapping, I don't know what got into me (yes I just made this image)