Unofficial tier lists from well regarded players are also pretty bad though. And yeah, for the very top it might have less affect. But I feel like most tournament players really aren't going to win that many tournaments anyways, so money isn't the issue
In general, a tier list is formed on two basic elements:
1) Tournament placings (where a character typically places in tournaments or has shown to place in tournaments)
2) Match-up data
Both of which are not things the community has
this early on. A lot of what makes "early" tier lists bad is the fact that there's no data to back it up -- it's just gut feelings. However, most of the newer players or people that are trying to get into the competitive scene don't have an understanding on what a "tier list" actually is or what makes up a tier list. A tier list isn't just someone's list on who they think the best characters are, it's a ranking list of who the best characters are based on data gathered from tournaments & match-ups.
People get so caught up in where characters are placed on the list + how often tiers are brought up that they forget that and the phrase "tier list" has ultimately lost meaning. That is, it's a phrase people throw around for
anything regarding how a character is in the game vs. what I explained above.
Early tier lists are generally avoided in Smash but there are definitely people out there who try to put out
something like a tier list and people will refer to it as a tier list despite how factually incorrect it might be or how it lacks the data to back it up. Those people who do that are either doing it for attention or to fill a need -- that need, being, to try and figure out or have an understanding on how "good" a character is. Unfortunately, those kinds of lists can have a negative effect on the meta where people are no longer playing characters they like, but rather characters that are higher up on this "early tier list" (even though it's not
actually a tier list).
So many people have this misconception about tier lists and that's the problem with it. If everybody knew and treated tier lists more seriously, we'd see less people craving for one so early from someone that's already good at the game.
Impressions on characters are fine, but you shouldn't advocate the idea that someone like ZSS is "top tier" in a game that's still largely unexplored. A rough estimate of where a character might rank on one is also kind of bad but not as bad as being explicit about their placement and/or making a full fledged "tier list" with no data to back it up.
I, generally, wouldn't worry about any "early tier lists" happening unless it comes from Mew2King. He tends to do stuff like that and it's a problem because a large portion of people take his word as gospel despite how time and time again, he's wrong. You only need to look into the past to see that and even more recently with PM. He doesn't realize just how much influence/say he has in the community and how much people value his opinions (it goes along with his other social problems he has, but it's not his fault he's got those issues... he has some form of autism).
I hope that quells some of your worry.