Jennifer Maas TV Business WriterFox hopes to greet a big audience with its new small-town docu-comedy “Welcome to Flatch” when the Paul Feig and Jenny Bicks-produced show launches later this week. But if “Flatch” doesn’t bring in the viewers with its linear premiere on Thursday at 9:30 p.m., Fox execs won’t be talking about cutting the mockumentary from the network’s midseason lineup Friday morning.That’s because the broadcast network is launching the first half of the 14-episode Season 1 via Hulu and other digital platforms at midnight on Thursday, and promises it’s not going to be giving much weight to “Welcome to Flatch’s” Live + Same Day Nielsen ratings over those first seven weeks of airing, when the episodes will all be available for streaming well before they rollout weekly on Fox.