You cannot search for a style that you haven't applied to the text. However you can search for the background shading e.g.
Sub ReplaceShading()
'Graham Mayor - https://www.gmayor.com - Last updated - 05 Jan 2022 
Dim oRng As Range
    Set oRng = ActiveDocument.Range
    With oRng.Find
        .ClearFormatting
        .Replacement.ClearFormatting
        .Font.Shading.BackgroundPatternColor = RGB(232, 198, 201)
        .Text = ""
        .Replacement.Text = ""
        .Forward = True
        .Wrap = wdFindContinue
        .Format = True
        .MatchCase = False
        .MatchWholeWord = False
        .MatchWildcards = False
        .MatchSoundsLike = False
        .MatchAllWordForms = False
        Do While .Execute
            oRng.Font.StrikeThrough = True
            oRng.Font.Shading.BackgroundPatternColor = wdColorAutomatic
            oRng.Collapse 0
        Loop
    End With
    Set oRng = Nothing
End Sub