In recent years it has been fashionable for the USCCB to transfer feasts to the next Sunday. The thinking behind this should be obvious, we don’t want people to feel guilty because they don’t bother to come to Mass, so we will move the feast to Sunday so people can still celebrate it without guilt.
The truth is, the only people so busy they can’t feasibly get to Mass on Holy Days during the week are those who are excused from the obligation anyway, such as doctors, law enforcement and firefighters, or those disabled or without transportation. Everyone else has the ability. The Churches could offer Mass in the evening or early in the morning, and it is not such a sacrifice that it can’t be done. The issue is, Mass attendance has dropped off sharply since Vatican II, and gets worse, thus Holy Days only sharpen the reality of the problem.
But we know that people can go, and if the Ascension Mass remained on Thursday in the Novus Ordo, or its obligation remained in the Traditional Mass which retains the feast on Thursday, people could go without difficulty. The Novus Ordo makes it superbly easy, since they have the vigil Mass the night before (which in my opinion is a mistake to offer carte blanche, because it is an occasion for abuse and degradation of Sunday, but that is for another day, the point is, they make it extremely easy). How do we know that everyone can go?