Noticed this after my morning ride today and I'm not sure what to make of it. To my eye, it looks like the tube has wrinkled slightly, however, I can't think of how it could have happened (no crashes, etc.). Additionally, there's no evidence of damage to the downtube as you would see from something like a front end collision. The only "hard" impact I can think of was from last week when I hopped down some stairs and did feel like the front wheel took a harder "thud" on the bottom step than expected. I inspected the wheel and fork afterwards and didn't notice anything off. I didn't look in this exact spot, but I was working on the frontend of the bike later that day in the shop stand and feel like I would have seen it during that time.
My plan is to chip off the paint a little to inspect the bare metal underneath to check for corrosion or cracks, though I'm not expecting to see any. Assuming that, I plan to just cover up the exposed metal and keep on truckin' given how minior any possible damage appears to be. I'm curious to see what people think, though. I've also reached out to Riv with the same photos to get an "official" opinion on the matter as well.