Try posting this in the feature suggestions forum. You posted in the forum where users get help with their mIRC problems.

https://forums.mirc.com/postlist.php?Cat=&Board=featuresuggestions

As for the feature, it's something a lot of applications are doing today, but it shouldn't be "silent" and automatic by default. If implimented it should prompt the users "do you want to check for updates".

The biggest problem is that it will generate a bit more web traffic to perform the update checks. And with as many users as mIRC has on a regular basis that can add up real quick.

Anyway, good luck with your suggestion.