So I read this thread one more time and I have to say I'm also a bit unsure what it's really all about.
Yes, Avast, when expired, sometimes gives the user a free grace period (after expiration), by auto-renewing its license for a little bit. This has been a feature of the product for at least a couple of years now.
We figured that it's better to keep the user in the loop than to leave his PC unprotected.
In practice, this is a fairly rare case though - mainly because of all the expiration messaging built into the product. Realize that in the last phase (product almost expired, or already expired), the expiration screens are displayed every 4 hours (and the actual act of re-registering takes maybe like 30 seconds, - or 1 minute if you're slow).
To that end, I have to say that I feel like ManyQs is maybe more about testing all sorts of corner cases than about actually using the product to let it do its job - i.e. protect his PCs (as most of our users do). I mean, how likely is the scenario where he ignores all the re-registration nag screens thrown at him every 4 hours (and every reboot), leaves the product completely expire (again keeping up with all the renewal screens) and then goes ahead and installs MSE on the box, without removing Avast first? And at the end of the day, be concerned that Avast eventually shut up and somehow miraculously reactivated itself?
If you don't like the product, that's fine, just get rid of it and move on. If you do like it and want to use it, we will be glad to welcome you back - and maybe even assist you with exploring some of the hidden features like the one you have just discovered - but I'm generally not a big fan of the tone you have chosen here, where you basically start blaming everyone around you and coming up with hypothetical corner cases where a perfectly valid feature is interpreted as something evil.
On a side note, full compatibility with MSE (Win7) and Windows Defender (Win8) is in our test matrix, meaning that you should be fine running these two specific AVs in parallel (I'm not saying I encourage you to do so, mainly for performance reasons, but I'm just saying that you shouldn't have any problems if you still decide to run both of the products together).
Thanks
Vlk