The lifecycle of @Dependent instances created through javax.enterprise.inject.spi.CDI is not well defined. In fact, the spec does not even define the lifecycle of javax.enterprise.inject.spi.CDI.
However, it would make sense to destroy such instances during shutdown. This works in Weld SE. But for other environments we should provide some guidelines or maybe some SPI and helpers. Currently, it's not possible to reuse the logic provided by Weld core easily. For instance, WildFly integration depends on org.jboss.weld.AbstractCDI and other Weld internals.