You're asking us to predict the future. I know that an importer from several popular forum software is planned, esoTalk being among those, but as to when that will happen and in what order I couldn't tell you. I don't think anyone can.
Best advice I can offer is to choose the software you see that fits your current needs and available hardware. I gravitate towards Flarum because of its PHP base, which makes it easier to install on my server alongside many other hosted sites, but you may have the opportunity to dedicate a whole (virtualized) server to your forum, and can choose anything that fits your needs.
I guess it really depends on what you're looking for.