Very interesting, to change the last name? Does a last name have any chashivus by us I understood its just a siman to know which sruly we are referring to
Did he change his name?
If we want to know which sruly we are referring to we just say sruly yankel's or sruly meilech's
IIRC there were some health issues in his family (might have been one of his children or his wife, or maybe several) at the time, or just prior.
While it's rather unusual to give such importance to a last name, I could speculate that since he was widely known, and his merits acknowledged, by his last name, there might have been some significance to it. But this is pure speculation and I definitely have no clue or understanding in the Rebbe's reasoning for this. The interesting thing is that the suggestion wasn't about changing the meaning of the name, but rather the language of the name.
