I think the only way to show the icon on the status bar with tasker is using the notification (notify task) and giving it an icon.

     Profile: Detect Auto-rotation setting change
    	Event: Custom Setting [ Type:System Name:accelerometer_rotation Value:* ]
    
    
    
    Enter Task: Un-notify if autorotate off
    
    A1: Custom Setting [
         Type: System
         Name: accelerometer_rotation
         Read Setting To: %arstat ]
    
    A2: Notify Cancel [
         Title: ar ]
        If  [ %arstat ~ 0 ]
    
    A3: Notify [
         Title: ar
         Icon: mw_device_screen_rotation
         Number: 0
         Priority: 3
         LED Colour: Red
         LED Rate: 0 ]
        If  [ %arstat ~ 1 ]
    
       

You can set the notification to silent.

I've used something called "System UI Tuner" in the past. It does what you ask, in that you can modify which status car icons are shown, amongst other things.

Haven't tried it recently, not sure it still exists or works with newer versions of Android.

No need for tasker, you can achieve the same thing by enabling rotation icon using systemui tuner and adb.

I had a quick look, and cant find a way to detect the auto rotate state.

What is your end goal out of curiosity? Do you juat want to have a visual notification of autorotate so you can turn it off? Because an alternative would be to automatically turn it on and off.

I use this:

https://taskernet.com/shares/?user=AS35m8n8aLszGBR%2Bqb%2FvaUMEVX6DHjPZv%2Ba%2F8L3D6HkyQQ%2FGVLhuUeN3Uhf03S5c%2FtdJpZye&id=Profile%3AAutoRotate

When in YouTube, Netflix, etc, it enables autorotate, and when you switch out it disables it again.

I found a way to get/set autorotation: https://stackoverflow.com/questions/25864385/changing-android-device-orientation-with-adb

Change "put" to "get" to query.

I don't know about adding icons. Perhaps it would be acceptable to just always set autorotate off at a certain time, or when you get home?

Personally, I almost always just keep it off, and on the rare occasion I have it on and forget, I just turn it off while my phone is rotated, and it goes back to portrait mode.

I also mainly don't use screen Auto Rotate, but I did make it a tile on the window shade. Rather than toggle it manually, I have Tasker enable rotation when an app that I want to auto-rotate is active on the screen, and disable it when that app is not active.

It doesn't put anything up on the status bar, but if you can live without it knowing only certain apps do it, maybe it doesn't matter.

    Profile: Auto-rotate Apps
    Settings: Restore: yes
    	Application: Sky Map, Camera, Gallery...
    
    
    
    Enter Task: Enable Auto-rotate
    
    A1: Display AutoRotate [
         Set: On ]
        If  [ %ROTATE_APP_LOCK Set ]
    
    A2: Variable Clear [
         Name: %ROTATE_APP_LOCK ]
    
    
    
    Exit Task: Disable Auto-rotate
    
    A1: Variable Set [
         Name: %ROTATE_APP_LOCK
         To: 1 ]
        If  [ %ROTATE_APP_LOCK !Set ]
    
    A2: Display AutoRotate [ ]