I think a lot of it is down to social media and the like. You always need to repaint your aircraft every so often so why not a special heritage scheme. It will show off your roots and heritage and will likely get a lot of free advertising through social media. I think that having trendy/hip/funny videos (which are always shared online by the airlines) is all about marketing and not to get people watching them. I think that craze is on the way out as even Delta are now showing their new bland video and gone is the one with subtle changes and they've even got rid of Deltalina.
I agree about some people being confused or anxious about flying on a supposed old school aircraft. I've heard a rumour of a BOAC livery appearing on a BA jet. That really will confuse. I'd like to see a retro easyJet one. The one with the silver engines and the 01582 number on the side!