I think that Baymax was inspired by the random beach guy with an ice cream that kept falling from Lilo and Stitch.
I mean, don't they look so similar?
Baymax texting in the street. Lilo takes a picture of a man holding ice
Also, Lilo and Stitch came out in 2003, while Big Hero 6 came out in 2015. Newer things gather inspiration from older things. This is an example.
But the thing is "Random Ice-Cream Wielding Man" looks like Mr. Bubbles, Lilo's therapist, from Lilo and Stitch. But they're probably not related because they have different skin tones.