TileDB and Hail are rather complementary. We have customers that use TileDB to store and manage their variants, and Hail to perform GWAS (by exporting from TileDB to Hail format). We are currently designing a tighter integration with Hail. This expands on our vision for a universal data engine that integrates with pretty much everything out there and does not lock you in a single framework (e.g., Spark).
That was our feeling about the two products as well, the limitations w/ TileDB-vcf though sort of forced our hands. I was (and still am) of the opinion TileDB would be a good variant store since it does do so many of the things we want and does them well