The thing about the BeOS guy to improve the file system and finder metadata issues does make sense, but I do not think that in itself would make classic that impossible. Apple would probably be cutting their own throat not to continue to include classic as an os x layer for a few years to come. You might even continue to see 9.2.x upgrades to have it work better with OS X.
The entire stage play with Steve showing a tombstone of OS 9 was merely a dire warning to developers to get their acts in gear. There will be no -developer support- for any classic apps.. all development should at the very least be CARBON if not Cocoa, or you are playing solo, as a developer, in a graveyard.