It seems like more of a false positive or soft glitch than anything else, as charging in 30ish degrees F doesn't make sense for it to be thermal gating issue.That is correct.
On the Ford F-150 Lightning, they fixed an air damn fault issue with an over-the-air update recently. The problems on the air dam are a less-than-optimal system for raising and lowering it.
The less-than-optimal system of course was not corrected with an over-the-air update. The parameters for when the warning light comes on was adjusted, so that people see those warnings far less frequently, if ever. There, customer not complaining, problem solved. Did it change the behavior of the air dam? No lol.
Since Rivian cannot change the actual physical cooling characteristics of the battery pack over the air, a similar fix can be expected. Instead of telling you why your dcfc is being throttled, they will remove that information and remove a lot of complaints in the process. There is precious little a manufacturer can do over the air to improve cooling while dcfc, except for possibly moving the entry and exit parameters.
Do I know for certain that is going to be the fix? No, I don't work for Rivian. But I was in the industry for 30 plus years, so I'm pretty familiar with how these things work.