You are deleting the table, which is probably where the warning comes from, whereas if you use a Delete query the set warnings will work.
Here is my code for importing various text files running some clean up queries an append query and then the delete query.

Dim FileNm, FilePathName, Path, FileNameList() As String
    Dim FileCount As Integer
    DoCmd.SetWarnings False
    Path = Me.FilePath
    FileNm = Dir(Path & "")
    Search_path = Path ' where ?
Search_Filter = "*.txt" ' what ?
Docname = Dir(Search_path & "\" & Search_Filter)
Do Until Docname = "" ' build the collection
    FilePathName = Path & Docname
    MsgBox FilePathName

    'DoCmd.TransferText transferType:=acImportDelim, SpecificationName:="pp OUTINGS", TableName:="pp OUTINGS", FileName:=FilePathName, hasfieldnames:=True
    DoCmd.TransferText transferType:=acImportDelim, TableName:="Test", FileName:="C:\Users\A C\Downloads\Benjamins.txt", hasfieldnames:=True

Docname = Dir
Loop

'MsgBox "Successful file imports. Updating Files", vbInformation
DoCmd.OpenQuery "pp NQH Delete <1100"
DoCmd.OpenQuery "pp NQH Delete Unknowns"
DoCmd.OpenQuery "pp OUTINGS update 2A Query"
DoCmd.OpenQuery "pp OUTINGS update 3A Query"
DoCmd.OpenQuery "pp OUTINGS update 4A Query"
DoCmd.OpenQuery "pp OUTINGS Append Query"
DoCmd.OpenQuery "Delete pp OUTINGS Query"

DoCmd.SetWarnings True
MsgBox "Updates Complete"

Exit Sub
errorcatch:
MsgBox Err.Description