Is it still supposedly against the rules to re-use mugs? I only ask b/c we just got back from our first trip (last night

) and I knew that I had read that you couldn't re-use on future trips. However, our Magical Express bus driver on the way to the airport was very chatty and one of the things he said was "Hey, if you bought one of those refillable mugs, did you know that you can bring them back on future trips? Just pack the mugs away with your suitcase so when you're ready to come back, you'll know where your mug is." He's worked for WDW for over 20 years in all different positions - resorts, parks, photopass, etc. (he's only been a DME driver for a month) so it's not like he's new or anything. I was just wondering if they changed the rules?