Is communion in the hand a liturgical abuse?

The answer to the question "is it a liturgical abuse to receive communion in the hand" is: yes and no.

Yes, it is an abuse to receive communion in the hand in those jurisdictions where no indult has been granted, and, no, it is not an abuse to receive communion in the hand in those jurisdictions where an indult has been granted. In the interview linked in the question, the document Memoriale Domini is mentioned. This is the relevant ecclesial document for this question. It says

When therefore a small number of episcopal conferences and some individual bishops asked that the practice of placing the consecrated hosts in the people's hands be permitted in their territories, the Holy Father decided that all the bishops of the Latin Church should be asked if they thought it opportune to introduce this rite. A change in a matter of such moment, based on a most ancient and venerable tradition, does not merely affect discipline. It carries certain dangers with it which may arise from the new manner of administering holy communion: the danger of a loss of reverence for the august sacrament of the altar, of profanation, of adulterating the true doctrine.

Three questions were asked of the bishops, and the replies received by 12 March 1969 were as follows:

1. Do you think that attention should be paid to the desire that, over and above the traditional manner, the rite of receiving holy communion on the hand should be admitted?

Yes: 597

No: 1,233

Yes, but with reservations: 315

Invalid votes: 20

2. Is it your wish that this new rite be first tried in small communities, with the consent of the bishop?

Yes: 751

No: 1,215

Invalid votes, 70

3. Do you think that the faithful will receive this new rite gladly, after a proper catechetical preparation?

Yes: 835

No: 1,185

Invalid votes: 128

From the returns it is clear that the vast majority of bishops believe that the present discipline should not be changed, and that if it were, the change would be offensive to the sentiments and the spiritual culture of these bishops and of many of the faithful.

Therefore, taking into account the remarks and the advice of those whom "the Holy Spirit has placed to rule over" the Churches,[11] in view of the gravity of the matter and the force of the arguments put forward, the Holy Father has decided not to change the existing way of administering holy communion to the faithful.

The Apostolic See therefore emphatically urges bishops, priests and laity to obey carefully the law which is still valid and which has again been confirmed. It urges them to take account of the judgment given by the majority of Catholic bishops, of the rite now in use in the liturgy, of the common good of the Church.

Where a contrary usage, that of placing holy communion on the hand, prevails, the Holy See—wishing to help them fulfill their task, often difficult as it is nowadays—lays on those conferences the task of weighing carefully whatever special circumstances may exist there, taking care to avoid any risk of lack of respect or of false opinions with regard to the Blessed Eucharist, and to avoid any other ill effects that may follow.

In such cases, episcopal conferences should examine matters carefully and should make whatever decisions, by a secret vote and with a two-thirds majority, are needed to regulate matters. Their decisions should be sent to Rome to receive the necessary confirmation,[12] accompanied with a detailed account of the reasons which led them to take those decisions. The Holy See will examine each case carefully, taking into account the links between the different local churches and between each of them and the Universal Church, in order to promote the common good and the edification of all, and that mutual good example may increase faith and piety.

So, we can see that this would continue to be a liturgical abuse in any bishops' conferences where the two-thirds majority vote of the bishops was not obtained. Furthermore, since the Holy Father has not changed the existing norms, but permitted communion in the hand only by way of exception, communion on the tongue should never be denied.

As an addendum to this question, the document also outlines theological and practical reasons why reception on the tongue is superior to reception of the Eucharist in the hand:

This method of distributing holy communion [on the tongue] must be retained, taking the present situation of the Church in the entire world into account, not merely because it has many centuries of-tradition behind it, but especially because it expresses the faithful's reverence for the Eucharist. The custom does not detract in any way from the personal dignity of those who approach this great sacrament: it is part of that preparation that is needed for the most fruitful reception of the Body of the Lord.[6]

This reverence shows that it is not a sharing in "ordinary bread and wine"[7] that is involved, but in the Body and Blood of the Lord, through which "The people of God share the benefits of the Paschal Sacrifice, renew the New Covenant which God has made with man once for all through the Blood of Christ, and in faith and hope foreshadow and anticipate the eschatological banquet in the kingdom of the Father."[8]

Further, the practice which must be considered traditional ensures, more effectively, that holy communion is distributed with the proper respect, decorum and dignity. It removes the danger of profanation of the sacred species, in which "in a unique way, Christ, God and man, is present whole and entire, substantially and continually."[9] Lastly, it ensures that diligent carefulness about the fragments of consecrated bread which the Church has always recommended: "What you have allowed to drop, think of it as though you had lost one of your own members."