Personally, with characters like Little Mac and Shulk, I feel tier lists are going to be odd. Little Mac is such an extreme character that just can't be placed. Shulk is a character that can probably used in many different ways.
Then we've got custom moves (which people are leaning towards allowing) that will just throw everything out the wazoo lol.
I would imagine most people would be opposed to early tier lists because they aren't accurate because they aren't based on a lot of data. Tier lists are made to give a general idea with a lot of data to make it accurate. Predictions are another story.
You would be surprised at the bolded. Heck, this doesn't even apply to fighting games either. Pokemon is the best example where this happens.