A dynamical dropdown list which autoupdates and autosorts alphabetically

Option Explicit

Private Sub Worksheet_Change(ByVal Target As Range)
Dim res, lr As Long, ws As Worksheet
If Not Intersect(Target, Range("B6")) Is Nothing Then
    Application.EnableEvents = False
    Call ADD_DVlist(Target)
    Range("B6").Validation.Delete
    Range("B6").Validation.Add Type:=xlValidateList, AlertStyle:=xlValidAlertStop, _
    Formula1:="=DV_List"
End If
Application.EnableEvents = True
End Sub

Insert in Sheet1 module: righ click on tab, "View code", copy/past code

In standard module

Option Explicit

Sub ADD_DVlist(tValue)
Dim res, lr As Long, ws

    res = Application.Match(tValue, Range("DV_LIST"), 0)
    If IsError(res) Then                ' New entry so update DV List
        Set ws = Sheets("sheet2")
        With ws
            lr = .Cells(Rows.Count, "A").End(xlUp).Row + 1
            .Cells(lr, 1) = tValue
            .Range("A1:A" & lr).Sort Key1:=.Range("A1"), Order1:=xlAscending, Header:=xlNo
      End With
    End If

End Sub

to add new names, simply type in B6