Participating in Mass is not actually considered celebrating. Excommunication does not exclude them from the obligation that every believer has to attend Mass every Sunday. They are only prohibited from receiving the Sacrament of the Eucharist, both inside and outside of Mass.
I also believe it is a step to far to say that they cannot pray the rosary. The key word in that clause is ‘celebrate’. If that meant that the excommunicated person had to avoid all sacramentals, then that would be impossible to enact in reality, as the Catholic Church readily admits that everything has the potential to be a sacramental, as it has been created by God, and as such, is able to convey special instances of God’s grace to the individual believer. Celebrate means that they cannot lead sacramental devotions or ministerially convey sacramentals upon others, such as the blessing of objects or the renewal of marriage vows. Participating in sacramental graces may even be accidental. For example, if one happens to glance at a crucifix and is unexpectedly moved by the Lord’s Passion, that is accidental participation in the sacramental that is the crucifix.