Well, part of the point of the “Experimental” section generally is that systems in that section are more prone to large changes than systems that are officially supported.
However, in the case of Behavior Trees, they are definitely not being removed! We hope to have the system ready to move out of the “experimental” section within the next few major releases (the sooner, the better). There may be significant changes in the pipe, but at point it’s likely we’ll keep backwards compatibility throughout the process. At the very least I’m sure we’ll have a process for any conversion steps required.
In addition to various licensees using it, we’re using Behavior Trees on Fortnite (among other projects), so it’s pretty critical that we not break the system as we move forward with it!