I have run and played D&D (sometimes exclusively) since the 80s until 5th edition came out. I was no longer interested in another edition after so many decades when I already had more than enough material to run games and campaigns for a lifetime. That's when I decided that I was no longer their target audience. The decision was ultimately mine, not theirs.
But since the interest from newcomers has grown immensely, I would be a fool not to offer to run it for those who specifically request it. In fact, the demand for good GMs is greater than ever. So I still invest in the core books, as well as the Starter/Essential sets for teaching the game, and a couple campaign books that strike my fancy.
Most notably, I have bought everything I can find to run the ultimate Tomb of Annihilation campaign, including several support products from DMs Guild. Nothing else in 5e has really grabbed my attention before or since.
Of course, since I have discovered other systems offering different kinds or experiences and styles of play, 5e (and D&D in general) are no longer my preferred games of choice. But that doesn't mean they're not a choice at all, either. And maybe one day WotC, or someone else, will put out a D&D product that will get my interest again, or at least for that particular line or product.
My point is you don't need to be married to one system or edition to become a part of their "target audience". If you're a living, breathing consumer with expendable income looking for something to spend your time and money with, you're a target for them. Whether you choose to be a part of that audience is entirely up to you, and there is no commitment necessary. I may never run or play another D&D game again, or I might go back to an earlier edition. That might remove me from their perceived targets for marketing, but I am still a part of the audience.