SN 22.59 states experiencing Nibbana requires the dispassion (viraga) that occurs from completely realising the impermanence, unsatisfactoriness & not-self of every type of consciousness & the other four aggregates.
Now what do you think of this, O monks? Is consciousness permanent or impermanent?
Impermanent, O Lord.
Now, what is impermanent, is that unsatisfactory or satisfactory?
Unsatisfactory, O Lord.
Now, what is impermanent, unsatisfactory, subject to change, is it proper to regard it as: 'This is mine, this I am, this is my self'?
Indeed, not that, O Lord.
Therefore, surely, O monks, whatever consciousness, past, future or present, internal or external, coarse or fine, low or lofty, far or near, all that consciousness must be regarded with proper wisdom, according to reality, thus: 'This is not mine, this I am not, this is not my self.'
O monks, the well-instructed noble disciple, seeing thus, gets wearied of form, gets wearied of feeling, gets wearied of perception, gets wearied of mental formations, gets wearied of consciousness. Being wearied he becomes passion-free. In his freedom from passion, he is emancipated. Being emancipated, there is the knowledge that he is emancipated. He knows: 'birth is exhausted, lived is the holy life, what had to be done is done, there is nothing more of this becoming.'"
This the Blessed One said. Pleased, the group of five monks were delighted with the exposition of the Blessed One; moreover, as this exposition was being spoken, the minds of the group of five monks were freed of defilements, without attachment.
Indeed, at that time there were six arahants in the world.
Many suttas describe Nibbana as the ending of the perception (sanna) & asava (defilement) of 'becoming' (MN 121) and the calming of all formations (MN 26; sabbasamathosankhara).
Therefore, can the thought of or belief in 'rebirth' in the mind result in Nibbana?
Is the belief in 'rebirth-reincarnation' not a type of 'becoming' & not a 'thought formation'?