I also agree that this a good idea, however, if they decide not to submit it wouldn't reach Avast to check for malware.
It doesn't affect you at all from protection perspective if someone refuses to submit the file to avast!. If you don't want it submitted, so be it. If your intentions were to create a malware, you'd be forced to submit it either way, otherwise you can't be sure it's not already being detected by certain cloud, making it ineffective against anyone who's using avast!. Which is kinda a good thing from cloud systems. Malware writers are forced to send the stuff to it and exploit a tiny window in which it might still do damage. Or just speculate it won't be detected and just go on with it. In either way, avast! users have the upper hand, really.
I kinda understand why developers don't want their development binaries being submitted to the cloud, because they might be unprotected and they don't feel trust itself is enough. I'm confident that same devs don't mind final binary being submitted to the cloud though since it would happen either way when it reaches customers who use it and happen to have avast! installed. So, at that point, it doesn't really matter. But it does during development.
