Yeah, that period was a slog.
Speculation became boring real quick when everyone narrowed it down to four realistic choices in about a day or two, with most people leaning towards either Spring Man or Min Min.
I remember leaning towards 2 options:
1. Hero scenario with any of the following characters being the default and the alts:
Spring Man
Spring Girl
Min Min
???
Looking back at it, me and other people who thought this was likely didn't know jack**** about the Arms games. I never played Arms myself, but I was cheering for our ramen girl because out of them all, she looked like the coolest and most unique to me Arms character to me.
2. Min Min because of her not only winning the Party Crash, but because I really, REALLY preferred her over the other Arms characters even though I didn't know jack**** about them lol! But yeah, I put more stock on Spirit Min Min getting promoted over Assist Trophy Spring Man and I won. Nothing against Spring Man, but I find his design and conspect bland in comparison to Min Min's. I also think the first Assist Trophy promotion will be someone VERY popular the fans want like Waluigi or Isaac.