It is true that item 7 of
Immensae Caritatis allows for reception of communion a second time in a day, apart from participation in a Mass, which conflicts with Canon 917.
No, it is not lack of provision for fulfillment of Mass obligation like Canon 1248 which originally was given for ease (
Eucharisticum Mysterium, n. 8 - May 25, 1967). That same instruction also allowed reception of communion on Sunday anticipated Mass on the prior evening, and that provides a
reason for the second reception by a participant at a Mass which was repeated in
Immensae Caritatis:—on Saturday evening or the evening before a holy day of obligation, when they are fulfilling the obligation to assist at Mass, even if they have received communion that morning;3
Code:
—at the second Mass of Easter Sunday and in one of the day Masses on Christmas, even if they have received communion at the Mass of the Easter Vigil or at the Mass at Midnight on Christmas;4
—also at the evening Mass on Holy Thursday, even if they have also received communion at the chrism Mass.5
Also Canon 917 allows for reception of communion a second time in a day by a Mass participant at Masses which are not allowed per
Immensae Caritatis, for example a Communion Service in the morning and a noon Mass on a weekday.
adoremus.org/eucharisticummysterium.html
adoremus.org/TresAbhinc.html
adoremus.org/Interoecumenici.html