The reason for the placement of the Sign of Peace in the Liturgy is so that before we come forth to receive the Body of Christ we may have the occasion to reflect on the Mystical Body of Christ to which we belong. If the the parish church is large with a relatively small number of people seated half a dozen pews from one another, the pastor my wish to use the season of Lent to deepen the meaning for the Sign of Peace among his congregation. Then again, the pastor may have observed that the congregation is divided into factions so that people greet only certain parishioners and ignore some others, therefore he may hope that this Lenten adaptation may lead the factions toward a greater unity in Christ. In any event, I think it best to presume that the pastor has good intentions for this change rather than to imagine he is playing fast and loose with the rite.