While not related to vocal "warm ups" there is another important concept to using vocal cues for phrasing passages on the trumpet. Another teacher, not necessarily formally but though default, actually his fault for choosing me for his quintet, Eddie Brookshire (a bassist) taught me the importance of reading the words written UNDER THE NOTES when they are present that takes priority over the notes that may be written above the words. Here is Eddie's wisdom behind this concept:
Eddie sees the notes written as the song writer's way of "graphing" the phrasing of the lyrical component to a song. Songs are there to provide a message, and there is no stronger way to provide that message from the intent of the song writer then reproducing the word phrasing. But sometimes as Eddie describes, the graphical depiction of that quarter note, eighth note, dotted eighth note to sixteenth note just cannot accurately "graph" the spoken, written intent of the phrase. To get around this, just read the words, not the notes, and your phrasing as to the intent of the song writer will be spot on.