Sorry to enter this thread rather late. The confusion is about the word “acolyte” which has various meanings. Basically “acolyte” means assistant or dogsbody.
Before Vatican II, there were a number of stages between layman and being ordained priest. That determined how high you were allowed to progress up the altar steps during Mass. Acolyte is one of those stages and an instituted acolyte was in charge of the unconsecrated wine and the candles. The rank of instituted acolyte still exists in the process of becoming a priest or permanent deacon, but it tends to be a transitory phase lasting only a few weeks.
The General Instructions of the Roman Missal envisage a way of celebrating Mass where there is just one adult altar server who pours out the wine and turns the pages of the Missal. That individual is described as an acolyte although it is usually carried out by a non-instituted layman. Where there is an instituted acolyte available, he should carry out this role. With the permission of the ordinary, any properly instructed layman may carry out this role and in some provinces, including England and Wales, that layman might be (gasp) female. Confirmation makes you a full adult member of the Catholic Church and there is no reason why a teenager should not be appointed to this role - although that doesn’t make it compulsory.
Larger churches like mine can have a large number of altar servers ranging in age from 7 to well into their 70s. The person who takes charge of the altar servers, allocates their duties and generally organises things is known as the MC. This might not necessarily be the same as what is described in the General Instructions of the Roman Missal as the Master of Ceremonies. The MC usually takes on the duty of turning the pages of the Missal. We train our altar servers how to be MC once they have been confirmed although it may take a few years before they are confident to take charge of a Mass. That means we often have teenagers turning the Missal pages. For many years, I was one of a pool of Masters of Ceremonies that accompanied our Archbishop on pastoral visits. I was 17 when I started doing that job - it was 3 Archbishops ago, how time passes!
The lights that accompany the processional cross are properly called acolyte candles (they are acolytes to the cross rather than the priest) and the altar servers carrying them are often called acolytes. This all causes so much confusion, we’ve stopped using the word altogether.
