I know many fans are averse to Indra's Mangekyou Sharingan pattern being changed in the anime, as it differs from the pattern used in the manga. Personally, I don't really mind it either way.
If Indra's Mangekyou Sharingan is the same as Sasuke's Mangekyou pattern, then it stands as symbolic bookend to the start and conclusion of the Asura/Indra conflict, with Indra starting the ongoing conflict with his brother's spirit, a fight that lasted over centuries, and Sasuke being the one to end it when he reconciled with Naruto and choose to befriend and ally with Asura's reincarnation. Additionally, Sasuke rejected Indra's philosophy (that strength is found in one's own individual strength and independence) and instead chose to follow Asura's philosophy (that strength is found in teamwork, unity, and harmony). So Indra and Sasuke sharing the same Mangekyou pattern stands as poetic symbolism of the beginning and end of that conflict.
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Sasuke possessing the same Mangekyou pattern as Indra Otsutsuki marks Sasuke as the last of Indra's reincarnations, assuming Indra's reincarnations end with Naruto and Sasuke, which I personally figure to be likely so long as Indra's will is synonymous with Asura's will, as both reincarnations are for once philosophically on the same page. So long as the conflict between the two is resolved, then theoretically Indra will not reincarnate again. And if Indra doesn't reincarnate, then Asura won't reincarnate in response.
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That, or possibly the two brothers will continue to reincarnate but with the conjoined purpose of wanting to mutually protect their world rather than being at odds. In which case the reincarnation cycle would continue with the agenda changed. Either way, Sasuke ended one reincarnation cycle for good, with the possibility of starting a new reincarnation cycle. Though personally, I think it's more probable (and the general consensus among the Naruto fanbase) that Naruto and Sasuke ended the cycle once and for all.
Of course, many fans complain about the anime version of Indra's Mangekyou not being canon, as Indra was shown to have a different Mangekyou pattern in the manga, a swirl pattern.
Personally, I don't really have a preference either way, but I can say that manga canon trumps anime canon, so I concede that the manga version should be taken more seriously as the official canon version (though mostly I would just go for whichever design you prefer more or feel fits better).
Indra having a unique Mangekyou does continue the whole "every Mangekyou Sharingan pattern is unique" thing (though I hardly think a reincarnation awakening his predecessor's pattern really detracts from the uniqueness of the design either way).
It also perhaps reinforces my theory that the Mangekyou Sharingan patterns are hereditary, since the swirl pattern is reminiscent of Hagoromo's Rinnegan. It's probably patterned that way because Indra has a higher concentration of Otsutsuki alien blood than other Uchiha, since he is 25% Otsutsuki, so it makes sense that his Mangekyou pattern would be more similar to the Otsutsuki's Rinnegan than the Mangekyou patterning of his descendants would be, since Indra's descendants would have increasingly diluted Otsutsuki blood. The bloodline would grow further and further from the Rinnegan-possessing aliens, and as the Sharingan evolved, the patterns became more diverse and unique and presumably increasingly less reminiscent of the Rinnegan.
