No. This is completely unnecessary. There is an extremely simple solution that I keep posting and people keep ignoring.
We don't need lockouts, we don't need to hide progress, or anything else.
All we need is one simple thing: Have the "Join in Progress" button actually do what it says 100% of the time. People who check this box should simply not be matched with new parties. How hard could that be? They get to join in progress like they want, people who lost members in a dungeon still get replacements, and new parties do not get bothered or annoyed by queue withdrawals.
Everybody wins this way. I don't know why people aren't seeing it.