I think Parler will be a fascinating experiment in the type of community that eventually gravitates to it, especially those that leave Twitter for it. Will there be a cat-and-mouse game to see how to consistently troll without getting banned, sort of like the games Chinese play with their censors?
It will either turn into a real grown-up community with real content moderation and guidelines and nontrivial spend in automated and manual content removal or turn into a useless cesspit like Voat.
We've seen this experiment repeat itself over and over again in internet communities, there is little value in repeating it again with no novelties.