YES, it is true.
Refer Para
7.6.3 Missed ejbRemove() calls from
ejb specs:
The Bean Provider cannot assume that the Container will always invoke the ejbRemove() method on
a session bean instance. The following scenarios result in ejbRemove() not being called on an
instance:
• A crash of the EJB Container.
• A system exception thrown from the instance’s method to the Container.
• A timeout of client inactivity while the instance is in the passive state. The timeout is speci-fied
by the Deployer in an EJB Container implementation specific way.