No - mine was older than Suzy's - I ran into a number in that era - ie mid 70s to mid 80s. I'd never seen one as new as hers. But it sounds like hers is different - the top of the keys, whereas the top of mine are fine.
I've got some photos in a slide show which I did for something completely different recently - for my children, even a niece - showing that they - and my grandchildren were all played to by me - (there are a few others of them playing instruments when older (one has B.Music, other went to Conservatorium) too).
The slide show is at https://www.youtube.com/watch?v=XJKGeUvnR0U
- and if you fast forward to 0:38, you can see me playing to my grand-son about 6-8 mths ago, look at the front of the keys, they're really brown, but the tops are fine. Earlier photos - eg at 0:29 show it at 12yrs old.
But because it was 25-30 yrs old when I noticed it - I didn't worry about contacting YAMAHA. The piano had done a lot of work by then, I'd studied a diploma, 3 children learned on it, I accompanied their exams up to Conservatory level practising on it, and used for various group rehearsals by the kids and their friends - I just looked at a DIY fix.