So imho a duuuh
You can frame it in that way, but one could easily frame it in another. The Mandalorian is THE launch show of Disney+, and it's likely that just about everyone who's subscribed to it already has probably watched at least a bit of the Mandalorian. For many, it will be the key reason they signed up to the service as early as they did. Netflix has tons more subscribers, of course, but to the vast majority of them, The Witcher is likely just another show that they may or may not get around to eventually.