From someone at Shul:
Before Pesach we say “Chag Kasher v’Samayach” – why the double greeting?
It covers all types –
the stay at home folks – we “know” they are going to have a kosher Pesach but with all the work, we wish them a Happy Yom Tov.
the hotel crowd – their preparation is easy so we know they will be happy – but we have to wish them a Kosher Yom Tov.