The myth that after an acarya departs his works are never to be edited

“There is no precedent in our sampradaya for posthumous, unapproved changes to an acarya’s books. If a devotee needs to clarify a previous acarya’s work for the understanding of his contemporaries, he writes a separate tika and appends it to the original work, leaving the previous acaryas’ commentaries unchanged. This is the accepted practice in the Gaudiya-sampradaya.” (This, verbatim, from a critic on the internet.)

History shows that the critic is wrong.

The fourteenth chapter of the Bhakti-ratnakara contains four letters written by Sri Jiva Gosvami to Srinivasa Acarya. In the first letter, Jiva writes that he is still proofreading/correcting the Bhakti-rasamrta-sindhu of Srila Rupa Gosvami, who by then had passed away.

Though the Bhakti-ratnakara contains some historical inaccuracies, these letters are accepted by all scholars as genuine. (The letters, though not translated in the Bhakti-ratnakara that circulates in ISKCON, appear on pages 632 and 633 in the Gaudiya Mission’s Bengali edition.)

Another example: In the purport to Caitanya-caritamrta (Madhya 1.35) Srila Prabhupada writes, "Sanatana Gosvami gave his Vaisnava-tosani commentary to Srila Jiva Gosvami for editing, and Srila Jiva Gosvami edited this under the name of Laghu-tosani. Whatever he immediately put down in writing was finished in the year 1476 Saka (A.D. 1554). Srila Jiva Gosvami completed the Laghu-tosani in the year Sakabda 1504 (A.D. 1582)." This was 24 years after Srila Sanatana Gosvami disappeared, in A.D. 1558,

So, returning to the critic's point: Commentaries, of course, form an essential part of the Gaudiya tradition, and commentaries are always distinct from the original works. But editing too (even posthumous editing) has a distinguished place in the tradition.