That is a good point. If they want a younger demographic, I'm not sure why they're not finding Insta/YouTube/TikTok personalities to advertise their products. We all know Dior is very good at that with their Youtube influencers (who also have Insta an TikTok, so they get exposure there too.)
They did recently bring in their Knot Collection this year and the Tiffany T1 collection in 2020. Also, a little while back they released the Hardware Collection in 2017.
I think the issue is that they're not selling as well as they did in the past. Despite releasing the recent collections with a lot celebrity advertisements, for one reason or another, I don't think they're hitting their projected sales.
A lot of people, at least here on TPF, compare Tiffany with other luxury jewelry houses, especially Cartier and VCA and will tend to put more money in other houses based on longevity and timelessness. And Tiffany doesn't seem to be quite there yet.
Also, the quota the SAs need to meet is quite high. I don't know what it was before LVMH took over, but I was recently told this year that the SAs need to each make $500,000 USD in sales
every quarter.