Google has no long-term strategy for tablets. Best I can tell, every few years some product owners get together to once again do Google's Big Push For Tablets For Real This Time We Swear and the initiative goes until they get their promotions and then it's forgotten until the next round a few years later.
If you buy this tablet and like it, don't expect a successor. They'll release something completely unrelated in a few years, it might be running Chrome OS, it might have a keyboard accessory, it might have a pen accessory, it might have absolutely abysmal performance[1]. It's a complete grab bag.
And this applies to basically all Google products and services.