Integrate into WildFly Preview native jakarta namespace variants of the taglibs artifacts the Galleon WildFly plugin is currently transforming when it builds the wildfly-preview feature pack or provisions a server using it.
The following artifacts are currently being transformed:
[INFO] EE9: transformed taglibs-standard-compat-1.2.6-RC1.jar
[INFO] EE9: transformed taglibs-standard-impl-1.2.6-RC1.jar
[INFO] EE9: transformed taglibs-standard-spec-1.2.6-RC1.jar
A possibility here is to move off of Apache Taglibs if they haven't produced EE 9.1 artifacts yet.