[p3lim]

local CoordText = WorldMapFrameCloseButton:CreateFontString(nil, nil, 'GameFontNormal')
CoordText:SetPoint('RIGHT', WorldMapFrameCloseButton, 'LEFT', -30, 0)
 
local totalElapsed = 0
WorldMapDetailFrame:HookScript('OnUpdate', function(self, elapsed)
    if(totalElapsed > 0.1) then
        if(WorldMapScrollFrame:IsMouseOver()) then
            local scale = self:GetEffectiveScale()
            local centerX, centerY = self:GetCenter()
            local width, height = self:GetSize()
            local x, y = GetCursorPosition()
 
            x = ((x / scale) - (centerX - (width / 2))) / width
            y = (centerY + (height / 2) - (y / scale)) / height
 
            CoordText:SetFormattedText('%.2f, %.2f', x * 100, y * 100)
            CoordText:SetTextColor(0, 1, 0)
        else
            local x, y = GetPlayerMapPosition('player')
            CoordText:SetFormattedText('%.2f, %.2f', x * 100, y * 100)
            CoordText:SetTextColor(1, 1, 0)
        end
 
        totalElapsed = 0
    else
        totalElapsed = totalElapsed + elapsed
    end
end)

What I use, this adds player (or mouse when hovering the map) position to the left of the close button.