The RC Novus Ordo pattern of readings (Old Testament, Gradual Psalm, New Testament, Alleluia, Gospel) at the mass is actually a restoration of the more ancient practice within the Roman Rite, which fell into disuse by the high mediaeval period. It is also the practice found in the Orthodox Western Rite in the Gregorian Mass used at the monasteries of Our Lady of Mount Royal in Florida, USA, and Christ the Saviour in Hamilton, Canada. This is also the pattern preserved in the Gallican Liturgy of St Germain of Paris. The Antiochene Liturgy of St James and the Alexandrian Liturgy of St Mark, both blessed for use within ROCOR, also have Old Testament readings, (although this may be considered optional in the latter due to the difference in Alexandrian practice over the centuries), so the use of the Old Testament at the eucharistic liturgy is nothing like the 20th-century Latin innovation that it is ocassionally portrayed as being.
The Ambrosian rite has an Old Testament reading. Nobody knows for sure what the Gallican rite had -- I wouldn't be surprised if it had an OT reading, but the "Liturgy of St. Germain" is a modern reconstruction and isn't evidence for anything.
I've never seen any credible evidence that the Roman rite ever had an OT reading as a standard part of the Mass. Do the ROCOR monasteries have an ancient lectionary they're using, or did they make one up?
(And what's with the insistence of many in the WR in referring to the Mass as "the liturgy"? It's the Mass! That's what it's always been called in the west! It's almost like they're trying to have the western rites without the Latin heritage that comes with them...)