Easter weekend on the Cote d'Azur

It is a busy travel period but otherwise, Easter is not as big in France as in some other countries, when it comes to holiday disruptions. The only day off is the Monday, and most things stay open these days. As for the Sunday, whatever is typically open on any Sunday will most likely stay open on Easter Sunday.

It’s as balso said. There could be more family meals on Sunday, a few traditional recipes and foods, but it’s a secular country so a holiday is a holiday no matter what the origin may have been. Expect a bit heavier traffic on the highways on Friday and Monday. Some chocolate rabbits and eggs in the shops. However, after Easter the European school trips to each others’ countries begin and tourism is in full gear. All the businesses that were closed for the winter reopen.

The only change you have to consider is lunch/dinner on Sunday, you may need to reserve ahead. Holiday schedules on transport may be in effect.

The only chaos caused is if there is a strike on transport. April is a relatively calm month, but there is the spring holidays.

Some small museums along the Riviera are open fewer days per week in the winter and early spring. I remember seeing one that dropped to only three days a week for part of the year. It's not Easter per se that would be the issue, but I'd check museum websites for days and hours of operation so you don't take fruitless side trips.