Music literature is replete with cases where the composer wants a slight crescendo, a slight decrescendo, or a slight ritardando, but is afraid to ask for it.
The composer is afraid that the performer will overdo it, and the composer would rather have it not done than overdone.
Music teachers have told me something to the effect of "The composer is underestimating you! Show the composer that you can make a very slight (crescendo) (decrescendo) (ritardando) here and prove him wrong!"
There is a passage in the Verdi Requiem where the composer wants a pochissimo retard but was afraid to ask for it.
When Toscanini was recording the work, he sensed that that was what Verdi wanted, and he did it just right.
Verdi was pleased.
The usual place for a slight crescendo is in a melodic rise.
The usual place for a slight descresdendo is in a melodic fall.
The usual place for a slight ritardando is at the end of a section of a piece or an entire piece.
That seems to be true in this case.