Even if they had included this caption on a different poster, it would have worked just as well, all the characters are teenagers after all, and it likely would have gone by unnoticed.
Not all of the other captions attached to the other Power Rangers posters are even attempts at humor.
They could have just gone with a comment like that here and everything would have been fine.
While certainly, this comment was unintentional, it was also an incredibly poor coincidence.