It isn’t needed.
The Sacred Triduum of the Lord’s Passion and Resurrection starts with the Mass of the Lord’s Supper on Holy Thursday evening and ends with Vespers on Easter Sunday.
It is expected that the hosts needed for the Liturgy of Good Friday will be offered and consecrated at the Mass of the Lord’s Supper, and that there will be no further Mass until that of the Easter Vigil. Any of the Blessed Sacrament that remains from the Liturgy is to be kept in a safe place in the Sacristy or elsewhere. So the Tabernacle has no function during these days.
It is, like the absence of Mass on Good Friday, a reminder that the Triduum is really a period of fasting, including ‘fasting’ from the celebration of the Eucharist.
