Yes, but for the most part fan polls have been pretty consistent No matter where you go. I believe Most of the top spots outside of veterans being Isaac, Banjo-K, King. K, Ridley, Geno, Skull Kid, Crash, Sora, Shovel Knight and Shantae. If that is only a small percentile of the big picture, then these are your best bet of who placed high on the actual poll. In fact, I put up a reddit link last week of someone who compiled several fan polls to get a consistent number. Geno was 3 or 4 after Isaac and Banjo.
Youtube Views were only used to gauge how well a character for DLC was recieved and thus guestimate how well they sold. Used only in the context of what has happened in the past and to prove being a household name doesn't necessarily mean you are going to sell like hotcakes, as the argument was that Sephiroth's selling potential comes from his household name status, while adversely, Ryu who is more iconic and more of a household name arguably, was behind on views.
Yes of course business decisions and many unknown factors come into play. No one knows what was said behind the doors. Polls are not useless though. Fan demand and fan polls are exactly what brought us Ridley, King K. Rool, Shovel Knight, and Shantae's spirit. As Sakurai has also stated, the ballot is heavily considered when choosing characters for Smash. All the SE characters are viable, yes, however, we cannot ignore facts. We also understand the SE may have a differing viewpoint hence why its such an emotional rollercoaster every time a new piece of info is announced.