I guess I don't understand all the angst about this. I guess some folks are willing to be bent out of shape about anything.
I used to be a "teacher" in the infant room of a church preschool. It was always a preschool, and based on customer demand added a toddler and infant classrooms.
We followed the same calendar as the preschoolers. So we celebrated holidays, participated in the rodeo parade & Mardi Gras parade. I even was expected to post a weekly "curriculum" in our hallway just like the preschoolers.
It did no harm to dress up for Halloween, pass out valentines or "hunt" for Easter eggs. It added a little fun and interest to our day to day activities.
Do none of you with babies talk to them about the grocery store? "Celebrate" Christmas with a 3 month old? Include them in conversations (even though they don't talk?) Read them books (even if they can't read?) Put them in a cute outfit (even if a white onesie would suffice?) Babies learn so much just by being engaged and included "in life."
And day after day after day can get pretty boring in the same infant classroom if you don't change it up just a little. Same thing hanging out in your living room 40 hours a week with no change in routine.
So be happy they want to do something to celebrate the holiday. You don't Have to participate if you don't want to. It's completely optional.
But being all sour about it isn't necessary either. Enjoy having a daycare that does more than the minimum "change a diaper." A little love, enrichment, and FUN is good for babies too!