The de facto play testing period came about because most people did not follow the advice to get their games finished and submitted at least 1 week before the submission deadline to allow time for testing. For those that did the right thing, most did not make it known on the forum and there was a configuration issue whereby those submissions could not be seen. And some people were running late. Adventuron was good enough to extend the deadline by one week and allow people to do last minute bug fixes after submissions closed. The problem is that adventures take a long time to play and test and there are a lot of games that need playing and testing. Those doing the playing and testing are usually those that have submitted games themselves and they may be busy doing their own bug fixing. So everyone is flat out testing and bug fixing AFTER the submission period has ended.
Don't be under any false impression. Judging has started! There is no grace period. Your game may already have been judged by some of the judges, whereas others haven't got to yours yet. So, if you have bug fixes to do, do them as soon as possible to improve your chances of more judges playing the bug-free version.