Sony has never, not even an expansion release... patched on anything except a wednesday exactly because of this possible issue. Every LU and every expansion patch has been on a wednesday since launch.
"hotfixes" can go in at any time, and are usually considered either A) urgent enough (like plat dupe bug) or B) isolated enough (very focused and considered low probabilty to break anything)
Just blows that one of these hotfixes did cause a problem on a friday AND on a holiday weekend.
Still... I wouldn't be surprised to see even 'hotfixes' banned from friday deployments after this.