In a presentation (in Japanese, via SonyAlphaRumors) at CP +, a Sigma manager dropped a mention of a coming “Sport” zoom. Sigma typically puts the Sport badge on a lens if it reached the Art level of quality, but is of a focal range greater than 200mm.
A picture of the well-regarded 60-600mm Sigma zoom remained on the screen during this part of the conversation. Sigma has a long history of producing high quality, bright sports zooms (f/2.8 aperture) in the 100-300mm range. The Sigma 120-300mm f/2.8 DG OS was released eight years ago, and the firm has not yet produced a mirrorless-first lens in that range.