It already was a "specialist product for collectors and lifestyle hobbyists". That's what it was before 5e! The only people who bought products and played them were long-term diehards - there was little room and difficult entry for "casual" players.
I don't really agree, personally, but it hinges very heavily on definitions, so obviously it's arguable.
Personally, if I look at 4E D&D, it does not look to me like a product for "collectors and lifestyle hobbyists" by my definition, in terms of the actual books released. It looks like they're very much trying to serve an actual player-centric (even more than DM-centric) market, rather than pumping out stuff that's going to go straight on to someone's shelf to be read once and admired, but not used.
4E is interesting because miniature stuff was
absolutely about collectors and lifestyle hobbyists (not that the latter, I'm using hobbyist in a term that's differentiated from people who actually necessarily play).
Long-term diehards are not "lifestyle hobbyists" as I'd define them, because they still pretty much only buy stuff they intend to use, and they don't typically buy peripheral "style" products, like, say, plushies that relate to D&D. Do you see the difference I'm getting at? I imagine it's on me and my poor explanations if you don't.
As for "little room and difficult entry for casual players", I'm just not sure that's entirely true,
if we're claiming that's not true for 5E. 5E is only different from 3E/4E in one way - the rules themselves are fairly accessible, whilst still toward the crunchier end of complexity by RPG standards (like, maybe 7/10 where something like PtbA games are usually a 4/10 in complexity, and Rolemaster, some versions of Shadowrun and the like would be 10/10 - 3E with anything beyond the basics would be at least 9/10 if not also 10/10 - I would say there are a handful of eccentric games drastically more complex even than those but they're so far outside even the niche hobby "mainstream" they can be disregarded). The big difference in open-ness is just cultural, and pre-existed before 5E (we've got a whole other thread on why it came to have so much impact, but the rejection of gatekeeping and so on has nothing to do with 5E's rules or even DMing suggestions or the like).
I think what makes the difference between targeting people playing the game, and people collecting the game, or using it as a lifestyle thing would be shown in what material is focused on.
I think if D&D leans more and more collector/lifestyle-oriented, we'll keep seeing books like Spelljammer - high production values, very pretty, low amounts of actual material, and we'll see adventures keep being produced with a reading-centric approach, rather than a functionality-centric approach, possibly even amping that up.
Personally I think Dragonlance will be particularly interesting to see, because it looks like with the wargame associated with it, it's definitely targeting collectors/lifestylers rather than players/DMs primarily, but maybe it'll actually be eminently practical?