I think it's and either/or proposition on GPS vs BRP Connect. Any specific built in GPS would likely become obsolete over time, which is why the idea of including multiple GPS options, including Rever is such a great idea. The problem is that BRP Connect just doesn't work in any reasonable way, and appears to need a major overhaul even in my 2020 model. It is one of the least intuitive and poorly designed interfaces I have ever tried to use, and is extremely limited in function and compatibility (and not even all of the very few apps it works with even actually work).
I would think that had they included it, and further split their resources, it wouldn't be worth using at all. Apple CarPlay would have been their best option. (Just to be clear, I'm not down on my Spyder, I love it, but for high end phone connected tech, they really dropped the ball and need a serious update, assuming that is possible.)
I have found it most effective to mount my phone on my handlebars and bluetooth it to my helmet. My iPhone has great GPS options, including Rever (with functions offline), and does everything else I need it to (podcasts, music, phone calls) while I'm riding, and integrates all of it in a sensible way.