How to merge Mongo arrays by unique key?

Question

MongoDB

Given:
1. Array addTags = [ 'tag1', 'tag2', ... ]
2. Simple selection like condition = {param:"value"}
3. Object like this:

someObject {
  ...
  param: String,
  tags:[{
        name:String,
        timestamp:Date
    }]
}

Task:
Add the missing tags from the addTags array to all objects matching the condition selection based on the match between the name field and the addTags element. Assign the newly added tags a timestamp corresponding to the current time.
Question:
Is this solved by means of Mongo?
The solution "on the forehead" on JS seems to me painfully suboptimal, it is seen in the following spirit:

const tagDates = addTags.map(tag=>{name:tag, timestamp:Date.now()}
findMany(condition).then(
  foundObjects=>foundObjects.forEach(object=>{
    const newTags = mergeByName(object.tags, tagDates)
    updateOne({id:object.id},{tags:newTags}).then()
  })
)