I think later he made a statement that he had re-thought it

afaict only thing he’s re-thought is this:

Many years ago I posted that I could not see anything wrong about sex between an adult and a child, if the child accepted it.

Through personal conversations in recent years, I’ve learned to understand how sex with a child can harm per psychologically. This changed my mind about the matter: I think adults should not do that. I am grateful for the conversations that enabled me to understand why.

But as that blog post points out:

This statement from Stallman has been accepted by his defenders as evidence of his capitulation on pedophilia. I argue that this statement is misleading due to the particular way Stallman uses the word “child”. When Stallman uses this word, he does so with a very specific meaning, which he explains on his website:

Children: Humans up to age 12 or 13 are children. After that, they become adolescents or teenagers. Let’s resist the practice of infantilizing teenagers, by not calling them “children”.

— stallman.org, “Anti-glossary”

It seems clear from this definition is that Stallman’s comments are not a capitulation at all. His 2019 retraction, when interpreted using his definition of “children”, does not contradict most of Stallman’s past statements regarding sex and minors, including his widely criticized defenses of many people accused of sexual impropriety with minors.