I have to admit that I had a similar though as I have read through this thread.
Could it be that there are too many options?
That said, in this case, if it is a pastoral decision, then that’s that - it is the priest’s decision to make.
FWIW …
I don’t remember any of my RC cousins, who made their First Communions in the 70s and early 80s, ever having partaken of the Cup on the occasion. In fact, I don’t ever remember the Cup being offered over the many occasions when we would attend Mass with them on Sundays (when my dad had to work and we couldn’t go to our own EC church). This itself could have been a pastoral decision for all I know, as the parish did enjoy a large congregation and the pews were generally filled at each Mass. They did have the assistant pastors distribute the Holy Eucharist at every Mass, but again, only the Host was offered as I clearly recall.
As a consequence, partaking of the Precious Blood is something I have never done when attending Mass in the Latin Church, to this day. The reason? It was not part of my “formation” in the Latin Church, and the thought still makes me rather nervous. Funny to think of it that way, as I was never nervous receiving both Species via liturgical spoon in my own EC church. I shared this because IMHO this is the danger of not preparing these youngsters to receive both the Most Pure Body AND Precious Blood. Follow-up catechesis would be a necessity, so it seems.
That said, I can understand why some would be disappointed that this is not part of the First Communion experience. However, under current practices with later Confirmation and more universal offering of the Cup in general, there seems to be ample opportunity to engage these youngsters and get them accustomed to receiving both the Most Pure Body and Precious Blood, so that they are comfortable doing so throughout their adult lives.