Dear teachers,

Would you please explain the last sentence of the following paragraph to me?

The new-style parents - mostly the ones down from London - would be in the classrooms before school, after school, chatting to teachers and pupils even popping their heads round doors while lessons where in progress, with messages about aunties or swimsuits or lost packed lunches. Lots of pupils took packed lunches. Mr Rossiter didn't like that. It somehow loosened the school's grip upon the child. It smacked of change: change smacked of chaos.

Thank you for your help.
Hello, Hela!

"Smack" = "has the taste of (heralds)". "It" (I'm not sure what it refers to) has a taste of (heralds) change", and "change" has a taste of (heralds) chaos.
'smacked of' - 'had all the signs of'

Students: We have free audio pronunciation exercises.
I thank both of you very much. Emotion: smile

Have a nice day.

Dear friends,

It is my opinion that «it» refers to the inopportune appearance of the parents during lessons.

It is possible also that it refers to a trend for taking packed lunches to school, however. It is then more humorous, I think. Emotion: smile

Kind regards, Emotion: smile

Yes, I think it must refer to the appearance of the parents (+ all their messages). Since the "lots of children too packed lunches" seems to come as an explanation of the messages about lost packed lunches (the more are brought to school, the more can get lost), that wouldn't be what Mr Rossiter is talking about - a shame! -.
Teachers: We supply a list of EFL job vacancies
Thank you all for taking the time to answer my questions. That's very kind of you.Emotion: smile