What is very interesting about these comparatively recent documentary and archeological discoveries is not only what we can gather from the scraps of text themselves, but how they become part of a much larger puzzle. We can piece things together to build up a better picture of the true facts.
The hymn is clearly a prayer to the Blessed Virgin asking for her intercession and assistance in time of trouble. This shows continuity with the belief of the church down through the ages. I’m thinking “Mary Help of Christians.”
Therefore, if this hymn to the Virgin dates from 250 AD we can deduce that it must be a written record of an earlier practice. Think about it, by the time something is written down for use in the liturgy it must already have been in use for some time. Furthermore, if this prayer is part of a document that is a copy of another document, then this also indicates that the actual practice is earlier than the manuscript itself.
In addition to this, if the hymn-prayer is included in the liturgy, then it must be something which is approved by the church and in practice on a fairly widespread basis. If it is included in the liturgy, then the term “theotokos” was not simply a theological term or a theological concept, but something which was integrated into the worshipping and devotional life of the church from the earliest days.
That argument also goes the other way: if the term “theotokos” was used in a hymn-prayer venerating the Blessed Virgin, then a high view of her significance in the plan of redemption must also have been prevalent in the theology of the early church.
You want primitive Christianity? You want to worship like the “early church” then Marian devotion had better be part of it!