If Nirvanis, elemental buddhas and failed monads are not allowed to stay forever in the Ain, then what will happen to them? Isn't the destiny of everyone to eventually live in the Ain forever and attain deeper realizations inside the Ain? If that's the case, then will those monads who exhausted their 3000 cycles of manifestation return again in another mahamanvantara until they become masters or paramarthasatyas?
Here Master Samael states that the monads that fail leave the Absolute again in a new mahamanvantara:
Samael Aun Weor: With the greatest pleasure, my dear brother. In any case, then, the monads that can fail in 3,000 cosmic cycles are certainly rare, but it is not impossible that some fail. What does it matter in the ocean of the universal spirit of life, one resplendent wave more or one resplendent wave less? Simply, it is a wave that did not achieve self-realization and that is all.
Student: Such a wave is not going to enter the absolute, as you have just told me, because that is for Paramarthasatyas. Such a wave will live within the ocean of the universal spirit of life; and that's it.
Samael Aun Weor: It is clear that at the end of the mahamanvantara, such a wave enters with all the waves into the eternal, unconditioned abstract space of the unmanifested Sat. But it is also very true that when the dawn arrives, that wave comes out with all the waves; it is a bubble in the ocean that necessarily has to come out of the absolute. It could not stay in the absolute; only the self-realized waves of light can remain in the absolute, the logos that possess a christified, self-realized consciousness (which is ultimately the effort that all logos are making).
I want you to know that deep within each of us there is an inner logoi that aspires to consciousness. The logoi that manages to have consciousness becomes self-realized logos and all self-realized logos have the right to become Paramarthasatyas, that is, an inhabitant of the absolute, do you understand me?
Here he talks about the waves that enter into the Absolute without self-realization(after 3000 cycles), and then later they come out in a new Mahamanvantara with all other waves. He states that the only waves that are allowed to stay in the Absolute are the Paramarthasatyas and no one else.
the right to become Paramarthasatyas, that is, an inhabitant of the absolute
If the failed wave could stay forever in the Absolute and never leave, then it would become an inhabitant of the Absolute, a Paramarthasatya.