Using index sorting by default in _search - elasticsearch

Question

I am using ElasticSearch 7.6 and the Index Sorting feature which was introduced in 6.0.
What i am looking to do is to do a GET /myindice/_search without specifying sort and get documents based on Index sorting settings I have specified for my index and NOT insertion order.
My index as per the doc :
PUT twitter
{
"settings" : {
"index" : {
"sort.field" : "date",
"sort.order" : "desc"
}
},
"mappings": {
"properties": {
"date": {
"type": "date"
}
}
}
}
PUT twitter/_doc/a
{
"date": "2015-01-01"
}
PUT twitter/_doc/b
{
"date": "2016-01-01"
}
PUT twitter/_doc/c
{
"date": "2017-01-01"
}
My initial thought is that
GET twitter/_search
Should return doc C, B and A.
I get the following :
{
"took" : 1,
"timed_out" : false,
"_shards" : {
"total" : 1,
"successful" : 1,
"skipped" : 0,
"failed" : 0
},
"hits" : {
"total" : {
"value" : 3,
"relation" : "eq"
},
"max_score" : 1.0,
"hits" : [
{
"_index" : "twitter",
"_type" : "_doc",
"_id" : "a",
"_score" : 1.0,
"_source" : {
"date" : "2015-01-01"
}
},
{
"_index" : "twitter",
"_type" : "_doc",
"_id" : "b",
"_score" : 1.0,
"_source" : {
"date" : "2016-01-01"
}
},
{
"_index" : "twitter",
"_type" : "_doc",
"_id" : "c",
"_score" : 1.0,
"_source" : {
"date" : "2017-01-01"
}
}
]
}
}
As the documentation isn't clear at this particular subject and that all query are using sort :
https://www.elastic.co/guide/en/elasticsearch/reference/6.0/index-modules-index-sorting.html
Am I required to specify the sort order in the GET query (hence repeating the sort specified as the Index Sorting) ?
Thanks in advance for any diligent soul that could help me,