The tube that caused the AD has nothing to do with draining the bowl or causing corrosion in the bowl. The only way anyone would have ever known this tube had an issue is if they found it had fallen out or was too short to pass through the lower hole in the screen. It is pretty obvious they assume the tube was cut to correct length and are asking you to verify it was pressed into the top correctly.
https://support.cessna.com/custsupt/contacts/pubs/ourpdf.pdf?as_id=17526
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