You are correct tomorrows auction does not include non-filing UK properties.
You can't seize assets of a non-filer...but what little profits (If any..because those UK properties have a negative net value) have been streamed to the Debtor per the DIP agreement. Any cream was sent to the parent co.
If 2nd Lien holders get much out of this it will come from the eventual ch 7 liquidation of those subs.
Those subs are worth more sold in pieces than they are as a business.