The point is that Ash Wednesday, Palm Sunday, Easter, Good Friday are MAJOR holidays - yet Apple excludes them but includes St Patricks day? And many less observed “holidays” I see Christmas is included - why this & not Easter? Is it because iPhone sales/gifts are at Christmas & not Easter? Sad!
This is a user-to-user technical support forum. No one here would know why Apple does or doesn't include a particular holiday. You can let them know your feelings here:
Product Feedback - Apple
Meanwhile, consider the fact that if Apple included all the holidays from all the major religions practiced in the U.S., there wouldn't be room for much else on the calendar. Ash Wednesday certainly isn't a major holiday for all Christians. Many Protestant denominations don't really make much of it.