I don't have a lot of reliable sources for SIGMA and Tamron, which isn't for a lack of trying. One of the most asked questions I get is “when will SIGMA and/or Tamron launch RF lenses?” With my answer usually being that I have no idea.
That may have changed this week, as a good source for other areas of the industry told me that at least SIGMA would be addressing the RF mount in 2022. While the source wasn't privy to the actual roadmap, they did think that we'd see 3-5 lenses announced for the RF mount in 2022. The biggest roadblock for SIGMA is apparently manufacturing capabilities beyond just the issues from the pandemic. This does make some sense, as SIGMA has said in the past that keeping up with demand is an ongoing challenge.
As for Tamron, I haven't heard a peep about their plans.
More to come…