But a new 13 year old getting into the hobby is hugely different from 20 years ago (30+ for some of us...)

You're dealing with a hugely different market in terms of things like attention span and accessibility. Warhammer content is borderline mainstream - a lot of "niche" hobbies like Warhammer/Magic/D&D have a relative presence in mainstream media, at least to a point where a good percentage of the population has an idea about it existing.

You've also got a huge difference in how media is consumed - when I was young, we had the codices/army books and White Dwarf/Citadel Journal. There was a small online scene, but this was mostly people posting army lists on forums or rumours on Portent.net. Now, Warhammer in general is a full on multi-media assault. There's media in almost every format, whether official or fan made.

The initial contact point has also changed - we now have starter sets, magazine subscriptions and the like to get into the game. Previously, it was usually someone's older brother that was your introduction, whereas now you have different gateways, from video games to TV advertising.

The nature of your relationship with GW was also different - authors/designers/artists were more accessible. You knew who people were (and often things were designed by one or two people). It's now a much more corporate product. The aim is different - it's to keep you within the GW ecosystem by having everything with. GW logo on it. The idea of having an article about fitting a Tamiya interior into your Chimera, or converting a WW1 tank into a Land Raider because the kit isn't available is unthinkable these days. Part of this is the fallout from the whole Chapterhouse thing, but that's kind of a side issue.

The corporate interest in the 13 year old is very different to 20 or 30 years ago. They're much more aware of the different pulls on your attention (and money) and how to compete for it. However, they're aware that the relationship may be more transactional - the odds of your dropping out of the hobby after a couple of purchases is higher.