The 3 sentances regarding changing form and clothes/armor being destroyed, and magical items getting a save to avoid destruction if you're too big were all removed in the MM errata. Clothing and armor no longer are destroyed upon change if you're too big, it simply functions exactly as normal for alternate form: "Any gear worn or carried by the creature that can’t be worn or carried in its new form instead falls to the ground in its space"
Note that even without the errata, the lycanthrope ruining it's clothing was only for if your form was increasing size during the change, many people seem to miss the "if the new form is larger than the character's natural form"