In the Varaha Purana, in the section called "Rudra Gita", it is said:
70.30 - Meaning: In olden times, the residents of the Bhu Loka all worshipped Janardhana. Arriving at Bhuvar Loka, they stayed there and engaged in devotion to Keshava, attaining Svarga loka, and successively progressing to that abode which is (relatively) freed from sorrow.
70.32 - He (Hari) who is all pervading, and also ever associated with a form, became manifest before them [the rishis and devas including rudra]. He asked them, “what can I do for you, O best of all yogis, people of great intellect”?
70.33 - They offered obeisance to him [Vishnu], the ruler of the devas, the Lord of all and said: O God of Gods! All people are situated on the path to liberation. How will creation occur and who will then reside in hell?
70.34 - Asked thus by the devas, Janardhana spoke – “In the first 3 yugas, most of those who are competent to meditate will attain me”.
70.35 - In the last yuga (Kali), people who resort to me are very rare. I shall produce delusion which will confuse the people.
This question and answer seems to admit, by the Devas and even Narayana, that it is possible for everyone to be liberated and creation to not continue anymore.
Does this passage admit that there are a finite amount of souls in samsara? What do commentaries say about this verse?
Ramanujacharya in his commentary on the Brahma Sutras says, for this sutra, the following:
...so also the fact of the flow of creation going on from all eternity, 'As the creator formed sun and moon formerly.' [a Vedic verse]
From this he infers that there are an infinite souls in samsara because he interprets the Vedic verse to be saying that creation is always continuous.
But is there any scripture that explicitly says there are an infinite souls in samsara? How can this Purana verse be reconciled with the Vedic verse and the traditional understanding that there are an infinite amount of souls in samsara and that creation is always continuous?