AT&T has accelerated the deliquescence of its advertising unit Xandr into WarnerMedia following last week’s concerning first quarter earnings. Unifying Xandr with WarnerMedia has been on the cards for months, as a strategy to harmonize operations and grow the technology’s powerful audience targeting potential to increase the value of ad slots. Ultimately though, lockdowns have prompted AT&T to patch over cracks before the situation intensifies. The new combined business will fuse all go-to-market and commercial efforts, with an eye towards innovating new advertising formats for HBO Max in 2021. If it wasn’t abundantly obvious before, then the crisis has emphasized how important HBO Max will be in AT&T’s future video business, paired with the advancement of its fiber and 5G network…