You may also read this thread in the mailing list [0]. I may need to look up some more resources, but it seems to me that there wasn't a rigorous peer review for it. For example, compare it to merging SM4 into OpenSSL [1]. I would've thought that you'd need a few rounds of back and forth reviews mostly focused on cryptography and implementation such as possibilities of side channel attacks etc., not just some comments on style once.
[0] https://lkml.org/lkml/2020/9/20/192 [1] https://github.com/openssl/openssl/pull/4552