In Sankara's Manīṣā panchakam we find the following excerpt -
If a person has attained the firm knowledge that he is not an object of perception, but is that pure consciousness which shines clearly in the states of waking, dream and deep sleep, and which, as the witness of the whole universe, dwells in all bodies from that of the Creator Brahma to that of the ant, then he is my Guru, irrespective of whether he is an outcast or a Brahmana. This is my conviction.
Also we find from his commentary to Vedanta sūtrās the following passage
The Sūdras are not qualified for that reason also that Smriti prohibits their hearing the Veda, their studying the Veda, and their understanding and performing Vedic matters. The prohibition of hearing the Veda is conveyed by the following passages: 'The ears of him who hears the Veda are to be filled with (molten) lead and lac,' and 'For a Sūdra is (like) a cemetery, therefore (the Veda) is not to be read in the vicinity of a śūdra.' From this latter passage the prohibition of studying the Veda results at once; for how should he study Scripture in whose vicinity it is not even to be read? There is, moreover, an express prohibition (of the Sūdras studying the Veda). 'His tongue is to be slit if he pronounces it; his body is to be cut through if he preserves it.' The prohibitions of hearing and studying the Veda already imply the prohibition of the knowledge and performance of Vedic matters; there are, however, express prohibitions also, such as 'he is not to impart knowledge to the Sūdra,'...
Now going through above sayings by him, we find both are mutually exclusive sayings.. A chāndāla or Sūdra (obviously his opinions are same for chāndālas as well as they are outcast) required to learn Vedanta to have BrahmanJnāna but at the same time Sankara is reluctant to let them study Vedanta to develop discrimination by which an outcast could become BrahmanJnāni ( or attain a firm knowledge he is none other than Brahman). Isn't this a deadlock condition? Or hypocrisy? Or wickedness?
It is like Sankara is cutting hands of outcasts & then saying "I will accept you my Guru if you feed me".