That is true with many updates to mIRC. And it's not limited to seeing a real error message instead of nothing. In fact, that change to $read to allow a real error message probably won't actually break very many scripts because most scripts are going to have been designed to not make use of having no error when the file doesn't exist. Other changes will affect many more scripts than that minor change.
This update is a huge update in order to make it support unicode. Khaled always works hard to keep mIRC as compatible with existing scripts as possible, but that's not always possible. Most scripts are going to need to be updated to work properly. Keep in mind that the public beta has been going on for a month or two prior to release and anyone who wanted to try and get their scripts updated before release had every opportunity to test the scripts and find the problems before release.
For example, I maintain the Invision script, which is a very large script. I had to make a LOT of changes to make it compatible with the new mIRC. I did so and we released it the same day as mIRC released. We had time to make the changes and test them and have it prepared for the new mIRC once it was released even though it's a very large script that required many changes. For scripts that are no longer being updated by the authors, anyone using them could have sought help in getting them updated during the beta period and still can ask for help now if they need it.
In the end, Khaled is not responsible for making mIRC work with scripts. The script authors are responsible for making their scripts with with mIRC. Like I said, Khaled does a great job in making it so that scripts usually don't break, but this new version had thousands of lines of code changes and you simply can't expect perfect compatibility with such a huge update.
