If I were an OSR publisher...

Then I would be looking at my upcoming catalog and seeing what I have that is remotely AD&D like and get it out in time for the reprints.

Think of the ads you could use.  You never have to claim compatibility except where the OGL is concerned.
"Love the new reprints of the Classic game?  Well you will also love..."

I have had the chance to talk to some younger generation gamers and many (but not all) are of the mind to get these, just to see what they are all about.

This could be one of the biggest PR opportunities to come in a very long time.

Posted in: 1st ed,Legacy DnD