These sections lift from Eucharisticum Mysterium 63ff. The CS post on EM 62-66 is here.
EM 63’s wording, “may” is strengthened into a “recommendation.”
86. In churches where the eucharist is regularly reserved, it is recommended that solemn exposition of the blessed sacrament for an extended period of time should take place once a year, even though this period is not strictly continuous. In this way the local community may meditate on this mystery more deeply and adore.
This kind of exposition, however, may take place, with the consent of the local Ordinary, only if there is assurance of the participation of a reasonable number of the faithful. [Eucharisticum Mysterium 63]
I suppose there’s work for the pastor to get a community unaccustomed to exposition to participate.
The bishop may “order” large parishes to provide exposition:
87. For any serious and general need, the local Ordinary is empowered to order prayer before the blessed sacrament exposed for a more extended period of time in those churches to which the faithful come in large numbers. [Eucharisticum Mysterium 64]
A provision for interruption:
88. Where there cannot be uninterrupted exposition because there is not a sufficient number of worshipers, it is permissible to replace the blessed sacrament in the tabernacle at fixed hours that are announced ahead of time. But this may not be done more than twice a day, for example, at midday and at night.
There is a simple ritual for reposition when exposition must be interrupted:
The following form of simple reposition may be observed: the priest or deacon, vested in an alb, or a surplice over a cassock, and a stole, replaces the blessed sacrament in the tabernacle after a brief period of adoration and a prayer said with those present. The exposition of the blessed sacrament may take place again, in the same manner and at a scheduled time. [Eucharisticum Mysterium 65]
Nothing really new here, but what do you make of parishes providing exposition at the bishop’s request? Is any reader aware of such an instance in their experience or hearsay?
89. Shorter expositions of the eucharist are to be arranged in such a way that the blessing with the eucharist is preceded by a reasonable time for readings of the word of God, songs, prayers, and a period for silent prayer.[Eucharisticum Mysterium 66]
Exposition merely for the purpose of giving benediction is prohibited.
How familiar are the Catholic laity with readings, songs, and prayers at these shorter expositions?
Catholic Sensibility 
Todd
I believe section 87 is intended to be the encompass the traditional Forty Hours Devotion, which was customarily promoted and monitored by bishops because of the detailed rubrical and liturgical demands the ritual long required since Pope Clement XII’s legislation regarding the devotion in 1731.
When I was younger, I recall our parish hosting a Forty Hours Devotion at the bishop’s direction. Can’t remember what it was for, though.
Forty Hours devotion was encouraged in the Boston Archdiocese during the Year of the Eucharist.